Extracorporeal blood processing methods and apparatus

ABSTRACT

An extracorporeal blood processing system is disclosed which includes a variety of novel components and which may be operated in accordance with a variety of novel methodologies. For instance, the system includes a graphical operator interface which directs the operator through various aspects of the apheresis procedure. Moreover, the system also includes a variety of features relating to loading a blood processing vessel into a blood processing channel and removing the same after completion of the procedure. Furthermore, the system also includes a variety of features relating to utilizing a blood priming of at least portions of the apheresis system in preparation for the procedure. In addition, the system includes a variety of features enhancing the performance of the apheresis system, including the interrelationship between the blood processing vessel and the blood processing vessel and the utilization of high packing factors for the procedure.

FIELD OF THE INVENTION

The present invention generally relates to the field of extracorporealblood processing and, more particularly, to methods and apparatus whichmay be incorporated into an apheresis system (e.g., blood componentcollection, therapeutic).

BACKGROUND OF THE INVENTION

One type of extracorporeal blood processing is an apheresis procedure inwhich blood is removed from a donor or patient, directed to a bloodcomponent separation device (e.g., centrifuge), and separated intovarious blood component types (e.g., red blood cells, white blood cells,platelets, plasma) for collection or therapeutic purposes. One or moreof these blood component types are collected (e.g., for therapeuticpurposes), while the remainder are returned to the donor or patient.

A number of factors affect the commercial viability of an apheresissystem. One factor relates to the operator of the system, specificallythe time and/or expertise required of an individual to prepare andoperate the apheresis system. For instance, reducing the time requiredby the operator to load and unload the disposables, as well as thecomplexity of these actions, can increase productivity and/or reduce thepotential for operator error. Moreover, reducing the dependency of thesystem on the operator may lead to reductions in operator errors and/orto reductions in the credentials desired/required for the operators ofthese systems.

Donor-related factors may also impact the commercial viability of anapheresis system and include donor convenience and donor comfort. Forinstance, donors typically have only a certain amount of time which maybe committed to visiting a blood component collection facility for adonation. Consequently, once at the collection facility the amount ofthe donor's time which is actually spent collecting blood components isanother factor which should be considered. This also relates to donorcomfort in that many view the actual collection procedure as beingsomewhat discomforting in that at least one and sometimes two accessneedles are in the donor throughout the procedure.

Performance-related factors continue to affect the commercial viabilityof an apheresis system. Performance may be judged in terms of the"collection efficiency" of the apheresis system, which may in turnreduce the amount of donation time and thus increase donor convenience.The "collection efficiency" of a system may of course be gauged in avariety of ways, such as by the amount of a particular blood componenttype which is collected in relation to the number of this bloodcomponent type which passes through the apheresis system. Performancemay also be evaluated based upon the effect which the apheresisprocedure has on the various blood component types. For instance, it isdesirable to minimize the adverse effects on the blood component typesas a result of the apheresis procedure (e.g., reduce plateletactivation).

SUMMARY OF THE INVENTION

The present invention generally relates to extracorporeal bloodprocessing. Since each of the various aspects of the present inventionmay be incorporated into an apheresis system (e.g., whether for bloodcomponent collection in which "healthy" cells are removed from the bloodor for therapeutic purposes in which "unhealthy" cells are removed fromthe blood), the present invention will be described in relation to thisparticular application. However, at least certain of the aspects of thepresent invention may be suited for other extracorporeal bloodprocessing applications and such are within the scope of the presentinvention.

An apheresis system which may embody one or more aspects of the presentinvention generally includes a blood component separation device (e.g.,a membrane-based separation device, a rotatable centrifuge element, suchas a rotor, which provides the forces required to separate blood intoits various blood component types (e.g., red blood cells, white bloodcells, platelets, and plasma)). In one embodiment, the separation deviceincludes a channel which receives a blood processing vessel. Typically,a healthy human donor or a patient suffering from some type of illness(donor/patient) is fluidly interconnected with the blood processingvessel by an extracorporeal tubing circuit, and preferably the bloodprocessing vessel and extracorporeal tubing circuit collectively definea closed, sterile system. When the fluid interconnection is established,blood may be extracted from the donor/patient and directed to the bloodcomponent separation device such that at least one type of bloodcomponent may be separated and removed from the blood, either forcollection or for therapy.

A first aspect of the present invention relates to enhancing the ease ofloading a blood processing vessel into a channel which is associatedwith a centrifuge rotor. In one embodiment of this first aspect, thecentrifuge rotor includes a blood processing vessel loading aperture inits sidewall which extends only part of the way through the centrifugerotor and then extends upwardly through the top of the centrifuge rotor.The centrifuge rotor thereby provides an opposing surface to the portionof the loading aperture which may be characterized as laterallyextending. The loading aperture within the centrifuge rotor may then beproperly characterized as being substantially L-shaped. When thedisposable blood processing vessel is inserted into this opening, it isdeflected upwardly through the centrifuge rotor. The operator may thengrasp the blood processing vessel and load it into the channel.

Another embodiment of this first aspect relates to a drive assembly fora centrifuge rotor assembly. The rotor assembly includes a rotorhousing, a channel mounting having a channel associated therewith, and asingle gear which rotatably interconnects the rotor housing and channelmounting. Through use of this single gear and by having this single gearbe radially offset in relation to the above-described loading aperturein the centrifuge rotor, the access to the loading aperture is notsubstantially affected by the drive assembly for the centrifuge rotor.For instance, by radially offsetting the single drive gear in relationto a plane which bisects the loading aperture, any counterweights whichare used to establish rotational balance of the centrifuge rotor will bedisposed so as to not adversely affect access to the loading aperture.

A second aspect of the present invention relates to the cross-sectionalconfiguration of at least a portion of a channel associated with achannel housing which is interconnectable with a blood componentseparation device. Generally, the channel itself is configured so as toretain the blood processing vessel therein during the apheresisprocedure. This is particularly desirable in the case of the bloodcomponent collection device being a centrifuge which is operated at highrotational speeds, such as greater than 2,500 RPM and even up to about3,000 RPM. In one embodiment, for at least a portion of the length ofthe channel a lip extends partially across an upper portion of thechannel.

The lip in this second aspect may be provided by configuring at leastone of the inner and outer channel walls with a generally C-shapedcross-sectional configuration. In this case, both the upper and lowerportions of the channel having the noted lip would have reduced widthsin comparison with the middle portion of the channel. These reducedwidth upper and lower portions of the channel may receive portions of ablood processing vessel which are sealed together. The channelconfiguration would then also serve to reduce the stresses experiencedby these seals when the blood processing vessel is pressurized duringthe apheresis procedure.

A third aspect of the present invention relates to a blood processingvessel, and more specifically to a blood processing vessel which may beeffectively loaded within a channel. In one embodiment of this thirdaspect, the blood processing vessel provides a continuous flow path byoverlapping and radially off-setting first and second ends and utilizingfirst and second connectors. The first and second connectors are eachpositioned between the two ends of the blood processing vessel,communicate with the interior of the blood processing vessel, and whenengaged facilitate the loading the blood processing vessel into thechannel in the correct position. One of the connectors may be astub-like structure which extends outwardly from the inner sidewall ofthe blood processing vessel, while the other connector may be astub-like structure which extends outwardly from the outer sidewall ofthe blood processing vessel.

Another embodiment of this third aspect is a blood processing vesselwhich is particularly useful for the channel described in the secondaspect above. In this regard, the blood processing vessel issufficiently rigid so as to not only be free-standing, but to be loadedinto the channel of the second aspect as well. However, the bloodprocessing vessel is still sufficiently flexible so as to be able tosubstantially conform to the shape of the channel during an apheresisprocedure. This is particularly desirable when the channel is shaped toprovide one or more desired functions regarding the apheresis procedure.

Once the blood processing vessel is loaded into the channel, at leastthe blood processing vessel must be primed. In this regard, a fourthaspect of the present invention relates to priming, preferably withblood. A channel associated with a channel housing, which is rotatablyinterconnected with a centrifuge rotor, includes a first cell separationstage. The first cell separation stage is sized such that a ratio of avolume of the channel which does not have RBCs to a volume of thechannel which does have RBCs is no greater than one-half of one lessthan the ratio of the hematocrit of blood entering the channel to thehematocrit of red blood cells exiting the channel. With thisconfiguration, blood may be used to prime the blood processing vesselwhen disposed within the channel, and thus the channel may be properlycharacterized as "blood-primable."

In one embodiment of this fourth aspect, the channel extends generallycurvilinearly about a rotational axis of the channel housing in a firstdirection. The channel includes, progressing in the first direction, thefirst cell separation stage, a red blood cell dam, a platelet collectionarea, a plasma collection area, and an interface control region forcontrolling a radial position of at least one interface between redblood cells and an adjacent blood component type(s) (e.g., a bully coatof WBCs, lymphocytes, and platelets). Blood introduced into the channelis separated into layers of red blood cells, white blood cells,platelets, and plasma in the first cell separation stage. Preferably,throughout the apheresis procedure and including the priming of theblood processing vessel, only separated platelets and plasma flow beyondthe red blood cell dam where the platelets may be removed from thechannel in the platelet collection area. This is provided by aninterface control mechanism which is disposed in the interface controlregion of the channel and which maintains the position of the interfacebetween separated red blood cells and the bully coat such that thiscondition is maintained.

Although the term "blood prime" is subject to a variety ofcharacterizations, in each case blood is the first fluid introduced intothe blood processing vessel. One characterization of the blood prime isthat separated plasma is provided to the interface control region beforeany separated red blood cells flow beyond the red blood cell dam intothe platelet collection area. Another characterization is that bloodand/or blood component types occupy the entire fluid-containing volumeof the blood processing vessel before any separated red blood cells flowbeyond the red blood cell dam into the platelet collection area.

One configuration of the channel which allows for a blood priming of theblood processing vessel when loaded within the channel is one in whichthe volume of that portion of the channel which principally containsplasma during the apheresis procedure is small in comparison to thevolume of that portion of the channel which principally contains redblood cells during the apheresis procedure. This allows plasma to beprovided to the interface control region of the channel before red bloodcells flow beyond the red blood cell dam into the platelet collectionstage to provide the red blood cell-bully coat interface controlfunction. That degree of "small" of the noted channel portion volumewhich allows for blood priming may be specifically defined in relationto a reference circle which has its origin on the rotational axis of thecentrifuge housing and which intersects the channel at a predeterminedlocation on the red blood cell dam. The volume of the channel whichprincipally contains separated plasma in the apheresis procedure isdisposed inside of this reference circle (e.g., V_(PL)) and the volumeof the channel which principally contains separated red blood cells inthe apheresis procedure is disposed outside of this reference circle(e.g., V_(RBC)). In one embodiment the ratio of V_(PL) /V_(RBC) is nogreater than about 0.3, and preferably no greater than about 0.25. Thisdesired ratio may be achieved by having the width of the channel betweenthe platelet collection area and the plasma collection area be less thanthe width of the channel throughout the first cell separation stage. Byutilizing this reduced width, the configuration of the channel betweenthe platelet collection area and the plasma collection area may utilizesubstantially vertically extending and planar inner and outer channelwalls.

A fifth aspect of the present invention relates to priming a bloodprocessing vessel disposed in a channel of a channel housing. Blood isused in the prime and the invention also accommodates for the removal ofair from the blood processing vessel during this prime. A donor/patientblood transfer assembly fluidly interconnects the blood processingvessel and a donor/patient, and may include an air receptacle forreceiving air which is displaced from the blood processing vessel by theblood priming. The various features associated with the channel of theabove-noted fourth aspect of the invention may be utilized in this fifthaspect as well.

A sixth aspect of the present invention relates to blood priming anapheresis system which includes a channel housing having a bloodprocessing channel associated therewith, a blood processing vesseldisposed in the channel and which has a blood inlet port, red blood celloutlet port, and an interface control port. The interface control portis used to control the radial position of at least one interface betweenseparated red blood cells and a blood component type(s) disposedadjacent the separated red blood cells.

A method of this sixth aspect includes the steps of rotating the channelhousing with the blood processing vessel positioned in its channel,introducing blood into the blood processing vessel to prime the same,and separating the blood into at least red blood cells, platelets, andplasma. The red blood cells are restricted from flowing beyond the redblood cell dam throughout the procedure, including in the priming of theblood processing vessel. In this regard, a flow of plasma is provided tothe interface control port before any of the red blood cells are able toflow beyond the red blood cell dam. Once this plasma reaches theinterface control port, control is established of the radial position ofthe interface between the separated red blood cells and the adjacentblood component type(s) such that the potential for red blood cellsflowing beyond the red blood cell dam is reduced. One or more of thevarious features discussed above with regard to the fourth and fifthaspects noted above may be incorporated into this sixth aspect as well.

A seventh aspect of the present invention is a method which may beutilized to prime a blood processing vessel disposed in a channel of achannel housing with blood. In this method, the blood processing vesselis disposed in the channel on the channel housing and a donor/patientblood transfer assembly fluidly interconnects a donor/patient with thisblood processing vessel. The method generally includes the steps ofinitiating the flow of blood from the donor/patient to the donor/patientblood transfer assembly while rotating the channel housing at a firstrotational velocity. Once the flow of blood reaches the blood processingvessel, the rotational velocity of the channel housing is increased to asecond rotational velocity. Once the entirety of the blood processingvessel contains either blood and/or one or more blood component types,the rotational velocity of the channel housing is once again increasedto a third rotational velocity. In one embodiment, the first rotationalvelocity ranges from about 180 RPM to about 220 RPM, and is preferablyabout 200 RPM, the second rotational velocity ranges from about 1,800RPM to about 2,200 RPM and is preferably about 2,000 RPM, and the thirdrotational velocity ranges from about 2,700 RPM to about 3,300 RPM, andis preferably about 3,000 RPM. Although a three-step approach may beutilized in the practice of the method of this seventh aspect, thecentrifuge speed need not stay at a fixed velocity during each of thethree "stages" (e.g., the first stage being priming the extracorporealcircuit from the donor/patient to the blood processing vessel, thesecond stage being priming the blood processing vessel, and the thirdstage being the remainder of the apheresis procedure). One or more ofthe various features discussed above with regard to the fourth, fifthand sixth aspects noted above may be incorporated into this seventhaspect as well.

An eighth aspect of the invention relates to priming the apheresissystem with blood. The apheresis system includes a channel housinghaving a channel associated therewith, a blood processing vesseldisposed in the channel, a donor/patient blood transfer assembly whichfluidly interconnects a donor/patient with the blood processing vesseland which includes a blood reservoir. A method in accordance with thiseighth aspect includes performing first and second drawing steps. Thefirst drawing step includes drawing blood from the donor/patient througha first portion of the donor/patient blood transfer assembly and intothe blood reservoir. After this first drawing step is terminated, theblood processing vessel is primed with the donor/patient's blood byperforming the second drawing step. The second drawing step includesdrawing blood from the donor/patient, through a second portion of thedonor/patient blood transfer assembly, through the blood processingvessel, and back into the blood reservoir. One or more of the variousfeatures discussed above with regard to the fourth, fifth, sixth, andseventh aspects noted above may be incorporated into this eighth aspectas well.

A ninth aspect of the present invention relates to the introduction ofblood into the blood processing vessel such that the blood may beseparated into at least two blood component types and further such thatat least one of these blood component types may be removed from theblood processing vessel via a blood component outlet port. The bloodprocessing vessel includes two interconnected sidewalls (e.g.,substantially planar surfaces which define the main body of thefluid-containing volume of the blood processing vessel) and the bloodinlet port extends through one of these sidewalls. Generally, the bloodexits the blood inlet port within the interior of the blood processingvessel in a direction which is at least partially in the direction ofthe primary flow of blood through the channel. This introduction ofblood into the blood processing vessel is subject to a number ofcharacterizations. For instance, the introduction may be characterizedas the blood exiting the blood inlet port into the interior of the bloodprocessing vessel at an angle of less than 90° relative to a referenceline extending perpendicularly to the channel wall which interfaces withthe blood inlet port. The introduction may be further characterized asexiting the blood inlet port in a direction which is substantiallyparallel with a direction of flow adjacent the blood inlet port. In oneembodiment, red blood cells may actually flow along the outer wall ofthe blood processing vessel past the blood inlet port such that thenoted introduction of blood into the blood processing vessel may befurther characterized as reducing the potential for disturbing this flowof red blood cells and/or as reducing an effect on flow characteristicsin the area of the blood processing vessel in which blood is introduced.The introduction may be further characterized as exiting the blood inletport in a direction which is substantially parallel with the sidewall ofthe blood processing vessel which interfaces with the blood inlet port.

A tenth aspect of the present invention relates to the removal ofplatelets from the blood processing vessel. This tenth aspect is basedupon the blood processing vessel and part of the adjacent channel wallof the channel collectively defining a generally funnel-shaped bloodcomponent collect well which collects at least one blood component typeflowing thereby (e.g., platelets). In one embodiment, the bloodprocessing vessel includes a blood inlet port and a first bloodcomponent outlet port. A support is disposed proximate the bloodcomponent outlet port and exteriorly relative to the fluid-containingvolume of the blood processing vessel. This support is contoured todirect the desired blood component type(s)toward the blood componentoutlet port and is in an overlapping relation with the exterior surfaceof the blood processing vessel. The support may be separable from theblood processing vessel such that it may be positioned between the bloodprocessing vessel and the associated channel wall after the vessel isloaded into the channel. The support may also be fixedly interconnectedwith the blood processing vessel in some manner. For instance, thesupport may be pivotally or hingedly interconnected with the exterior ofthe blood processing vessel to facilitate loading of the bloodprocessing vessel and/or to allow the support to move into apredetermined position upon pressurization of the blood processingvessel during an apheresis procedure to perform the desired function.Moreover, the support may be integrally formed with the associated bloodcomponent outlet port.

In another embodiment relating to this tenth aspect, the channelincludes inner and outer channel walls and part of a generallyfunnel-shaped blood component collect well is formed in at least one ofthese channel walls. That is, the remainder of the funnel-shaped bloodcomponent collect well is defined by the blood processing vessel, suchas described above in relation to the first embodiment of this tenthaspect. In order to allow the above-described blood processing vessel tobe effectively loaded into the blood processing channel, specificallyone of its blood component outlet ports, a blood component outlet portrecess extends radially beyond the portion of the blood componentcollect well defined by the channel wall (e.g., if the well is on theouter wall of the channel, this would be further radially outwardly,whereas, if the well is on the inner wall of the channel, this would befurther radially inwardly). This recess may also be configured so as toallow the above-noted contoured support, which interfaces with theexterior of the blood processing vessel, to move into a predeterminedposition upon pressurization of the blood processing vessel to directthe desired blood component type(s) into the blood component collectport.

In another embodiment of this tenth aspect, a method for processingblood in an apheresis system includes the steps of loading a bloodprocessing vessel in a channel on a channel housing. A contoured supportis disposed between the channel and the blood processing channel. Whenblood is introduced into the blood processing vessel and the channelhousing is rotated to separate the blood into various blood componenttypes, a generally funnel-shaped platelet collect well is defined byconforming one part of the blood processing vessel to the channel and byfurther conforming another part of the blood processing vessel to theshape of the support interfacing with the blood processing vessel. Inorder to further define this generally funnel-shaped platelet collectwell, pressurization of the blood processing vessel may move the supportinto a predetermined position. For instance, this may then allow thesupport to direct the platelets toward a platelet collect port on theblood processing vessel.

An eleventh aspect of the present invention relates to a control portwhich assists in automatically controlling (i.e., without operatoraction) the location of an interface between red blood cells and a bullycoat relative to a red blood cell dam. The red blood cell dam restrictsthe flow of separated red blood cells to a platelet collect port. Thecontrol port extends through the blood processing vessel and removesplasma and red blood cells as required in order to reduce the potentialfor red blood cells flowing "over" the red blood cell dam to theplatelet collect port. The "selective" removal of red blood cells fromthe blood processing vessel through the control port function is basedat least in part upon its position within the channel. That is, theautomatic control provided at least in part by the control port ispredicated upon the control port assuming a predetermined radialposition within the channel. In order to facilitate achieving thispredetermined radial position within the channel, the disposition of thecontrol port is provided independently of the thickness of the bloodprocessing vessel. Specifically, the position of the control port is notdependent upon the thickness of the materials which form the bloodprocessing vessel.

The desired objective for the control of this eleventh aspect of thepresent invention may be affected by interconnecting a support orshield-like structure with the control port and disposing this supportover an exterior surface of the blood processing vessel. This supportmay then be positioned against an interior surface of the channel,preferably within a recess which is specifically designed to receive thesupport. This support may also be more rigid than the blood processingvessel itself which reduces the potential for any significant change inthe radial position of the control port when the blood processing vesselis pressurized (e.g., any radial movement within a slot which receivesthe control port and which allows the control port to extend within thechannel). These support or shield-like members may also be used forother blood inlet/outlet ports on the blood processing vessel tosimilarly maintain the associated port in a predetermined positionand/or to reduce the discontinuity along the part of the channel withwhich the port interfaces.

A twelfth aspect of the present invention relates to a packing factorassociated with the separated blood component types in a separationstage(s) of the blood processing vessel. The packing factor is a numberwhich reflects the degree with which the blood component types are"packed together" in the separation stage(s) and is dependent at leastupon the rotational speed of the channel housing and the flow rate intothe blood processing vessel. The packing factor may be characterized asa dimensionless "density" of sorts of the blood component types in theseparation stage(s).

One embodiment of this twelfth aspect is a method which includes thesteps of rotating the channel housing, providing a flow to the bloodprocessing (e.g., the flow includes blood and typically anticoagulant aswell), separating the blood into a plurality of blood component types,and adjusting the rotational speed of the channel housing based upon acertain change in the flow rate. Since the packing factor is dependentupon the rotational speed of the channel housing and the flow rate intothe blood processing vessel, the methodology of this eleventh aspect maybe used to maintain a substantially constant and predetermined packingfactor. In this regard, preferably the packing factor is maintainedbetween about 11 and about 15, and preferably about 13.

Another embodiment of this twelfth aspect is a method for processingblood in an apheresis system in which a blood processing vessel isdisposed in a channel of a channel housing. The method includes thesteps of rotating the channel housing, providing a flow of blood(typically anticoagulated) to the blood processing vessel at a rateranging from about 40 milliliters per minute to about 70 milliliters perminute, separating the blood into a plurality of blood component typesin a first stage of the channel, and removing at least one of the bloodcomponent types from the blood processing vessel. Throughout theseparating step, a packing factor of at least about 10, and morepreferably at least about 10.2, is maintained in the first stage. Forflow rates up to about 50 milliliters per minute, the packing factor ismore preferably maintained at about 13 which may be achieved by rotatingthe channel housing at speeds greater than 2,500 RPM and typicallycloser to about 3,000 RPM.

Another embodiment of this twelfth aspect of the present inventionrelates to the configuration of a channel associated with a channelhousing which is rotatably interconnected with a centrifuge rotor. Thechannel includes a first cell separation stage and a first bloodcomponent collection stage which are separated by a cell dam. At leastone type of blood component is separated from remaining portions of theblood in the first cell separation stage and flows beyond the cell daminto the first blood component collection stage, while at least oneother type of blood component is preferably precluded from flowingbeyond the cell dam into the first blood component collection stage. Thewidth or sedimentation distance of the channel on the end of the firstcell separation stage disposed closest to the cell dam is less than thewidth or sedimentation distance of the channel on the opposite end ofthe first cell separation stage. In one embodiment, thewidth/sedimentation distance of the channel in the first cell separationstage is progressively reduced approaching the cell dam. When theabove-identified types of packing factors are utilized, this channelconfiguration may be used to reduce the volume of a buffy coat (whiteblood cells, lymphocytes, and platelets) between separated red bloodcells and platelets in the first stage, and thus reduces the number ofplatelet that are retained within the first cell separation stage.

A thirteenth aspect of the present invention relates to the rinsebackoperation at the end of the apheresis procedure in which attempts aremade to remove the remaining contents of the blood processing vessel andprovide the same back to the donor/patient. In one embodiment, one ormore ports of the blood processing vessel, which interface with thesidewall of the blood processing vessel, are configured in a mannerwhich reduces the potential for any closure of the port(s) during therinseback procedure due to interconnecting one or more pumps with theseports. The port(s) is configured so as to have an orifice displaced fromthe radially outwardmost end of the port. This may be provided byconfiguring the end of the port to have the orifice positioned betweentwo protrusions such that the orifice is recessed inwardly of theprotrusions. Consequently, if the opposing portion of the bloodprocessing vessel engages the protrusions during rinseback, the orificeis retained away from the blood processing vessel so as to not block theflow to the orifice.

In another embodiment relating to this thirteenth aspect, at least onenarrowed portion within the blood processing vessel extends downwardlyfrom at least one of the blood component outlet ports interfacing withthe sidewall of the blood processing vessel toward a lower portion ofthe blood processing vessel. As such, during rinseback a drawing-likeaction, for instance achieved by pumping from the blood processingvessel out the blood component outlet port(s), is initiated in a lowerportion of the blood processing vessel where the contents of the bloodprocessing vessel will be if rotation of the channel housing isterminated during rinseback as preferred. A second narrowed portion mayextend downwardly from the noted blood component outlet port such thatone passageway extend away from the port in opposing directions and suchthat the drawing-like action is initiated in two displaced locations.

A fourteenth aspect of the present invention relates to facilitatinginsertion/loading and removal of a blood processing vessel to and from,respectively, a channel associated with a channel housing uponcompletion of an apheresis procedure. Generally, the blood processingvessel may be removed from and loaded into the channel by engagingstructure which does not have any flow therethrough during the apheresisprocedure. This may be achieved by interconnecting at least one andpreferably a plurality of tabs or the like with the blood processingvessel. These tabs extend beyond the fluid-containing volume of theblood processing vessel and preferably extend beyond the channel whenthe vessel is loaded within the channel. As such, the tab(s) may begrasped by the operator of the apheresis system to load and unload theblood processing vessel to/from the channel. These tabs or the like maybe particularly useful when there is some resistance toinsertion/removal of the blood processing vessel from the channel, suchas when a lip is formed on the upper portion of the channel as discussedin relation to the second aspect.

A fifteenth aspect of the present invention relates to providing agraphical operator interface for the procedure. This graphical operatorinterface pictorially displays to the operator at least a portion of thesteps for the apheresis procedure, at least one of which requires sometype of operator action. These steps may be pictorially displayed in theorder in which they are to be performed. In order to further enhanceoperator recognition of the ordering of the pictorially displayedapheresis steps, the pictorials may also be numbered. Although thepictorials may alone convey to the operator the desired/required action,short textual descriptions may also be used in combination with thepictorials.

The pictorials may also be utilized to indicate the status of theapheresis procedure to the operator, such as by color or shadedifferentiation. For instance, three-way color or "shade"differentiation (e.g., in the case of colors using three differentcolors, and in the case of shade using the same general color butdifferent levels of "darkness") may be utilized to indicate to theoperator one of three conditions pertains to the step(s) associated witha particular pictorial. One color or shade may be utilized to indicatethat the step(s) associated with the pictorial are untimely (e.g., notyet ready for execution), while another color or shade may be utilizedto indicate that the step(s) associated with the pictorial are timely(e.g., ready for execution and/or are currently being executed), whileyet another color or shade may be utilized to indicate that the step(s)associated with the pictorial have been executed. The status may also beconveyed by providing further indicia that the step(s) associated with agiven pictorial have been completed.

The pictorials may further function as an operator input device. Forinstance, touch screen principles may be utilized such that the operatorwill touch one of the pictorials on the display when the operator isready to execute the step(s) associated with the pictorial. This touchscreen activation may generate one or more additional pictorials whichgraphically convey to the operator one or more steps or substeps whichneed to be undertaken at that particular time in the apheresisprocedure.

A sixteenth aspect of the present invention also relates to an interfacebetween the apheresis system and the operator. One embodiment of thissixteenth aspect is a method which includes the steps of instructing theapheresis system to address a first condition associated with theapheresis system by performing a first protocol. Typically, this "firstcondition" will be some type of problem associated with the apheresissystem which may be resolved in a multiplicity of ways (e.g., at leasttwo), such as by performing the first protocol or by performing a secondprotocol. That is, the methodology relates to "programming" theapheresis system to address or "correct" the first condition in one outof a plurality of ways and which does not allow/require the operator tomake any decisions regarding how to address or "correct" the firstcondition.

In this embodiment of the sixteenth aspect, the methodology includes thesteps of introducing blood into a blood separation device, separatingthe blood into a plurality of blood component types, and removing atleast one of the blood component types from the device. The methodologyalso includes the step of identifying the existence of the firstcondition relating to the apheresis system and thereafter having theapheresis system perform the first protocol. This "identification" ofthe first condition may be based upon the operator observing the firstcondition and inputting information relating to the existence of thefirst condition to the apheresis system. This methodology may beeffectively integrated into and/or utilize the graphical interfacediscussed above in relation to the fifteenth aspect of the invention.

Another embodiment relating to this sixteenth aspect relates to theapheresis system utilizing the operator to address potential problemsassociated with the apheresis procedure. A method of this sixteenthaspect includes the steps of introducing blood to the blood separationdevice, separating the blood into a plurality of blood component types,and removing at least one of these blood component types from the bloodseparation device. The method further includes the step of detecting thepotential existence of a"first condition" associated with the apheresisprocedure. This "first condition" is typically some potential problemand may be detected by the system itself (e.g., through appropriatedetectors/sensors/monitors), the operator, and/or the donor/patient.Once this first condition is detected, the operator is prompted by theapheresis system (e.g., via a computer interface) to perform aninvestigation of the system or a particular portion thereof. Theoperator is also prompted to specify the result of this investigation tothe system. Based upon the operator's response to the investigation, thesystem may prompt the operator to take further action (e.g., to addressthe first condition in a particular manner). Once again, thismethodology may be effectively integrated into and/or utilize thegraphical interface discussed above in relation to the fifteenth aspectof the invention.

A seventeenth aspect of the present invention relates to a disposableassembly for extracorporeal blood processing that utilizes a singlepressure sensing device to monitor positive and negative pressurechanges in both the blood removal line and blood return lineinterconnectable with a donor/patient. In one embodiment, a pressuresensitive diaphragm member contacts blood on one side within a module ofa molded cassette member, which cassette member may also include anintegrally defined internal passageway fluidly interconnecting themodule with both the blood removal and blood return lines. The use of asingle pressure sensor reduces component costs and complexity, andyields significant accuracy advantages.

An eighteenth aspect of the present invention further pertains to adisposable assembly for extracorporeal blood processing having a singleneedle for removal/return of whole blood/uncollected blood components, areservoir fluidly interconnected to the single needle for accumulatingblood components, and a gas holding means fluidly interconnected to thereservoir for receiving gas from the reservoir and returning the gas tothe reservoir as the reservoir cyclically accumulates and disposesuncollected blood components during a blood processing operation. In oneembodiment, the reservoir is integrally defined within a molded cassettemember. The provision of a gas holding means avoids a high internalpressure buildup as the reservoir is filled with returned bloodcomponents, thereby reducing gas entrainment at the liquid/gas interfaceand lowering the seal requirements for the reservoir and interconnectedcomponents.

A nineteenth aspect of the present invention relates to anextracorporeal blood processing device which includes a cassette memberhaving a reservoir for accumulating uncollected blood components, andupper and lower ultrasonic sensors positionable adjacent to thereservoir and being responsive to the presence or absence, respectively,of fluid adjacent thereto within the reservoir to trigger the start andstop of blood return cycles. In a related aspect, each of the upper andlower ultrasonic sensors may advantageously comprise a contact surfacefor direct, dry-docking with the reservoir, thereby avoiding the needfor the use of a docking gel or other like coupling medium.

A twentieth aspect of the present invention relates to an extracorporealblood processing device that comprises a cassette member having areservoir, at least first and second flexible tubing lines adjacentlyinterconnected to the cassette member in predetermined spaced relation,a collection means interconnected to one of the flexible tubing lines,and an interfacing valve assembly having a moveable member selectivelypositionable to occlude one of the tubings lines, such that in a firstmode of operation a separated blood component will be collected in thecollection means, and in a second mode of operation the separated bloodcomponent will be diverted into the reservoir. In one embodiment,multiple sets of corresponding first and second tubing lines/collectionmeans/and valve assemblies are provided, with each of the sets providingfor selective diversion of a blood component into a separate collectionmeans or common reservoir. Utilization of this arrangement yields acompact disposable that can be readily mounted relative to the divertvalve assemblies in a reliable manner.

A twenty-first aspect of the present invention relates to loading of adisposable cassette member having a plurality of tubing loops extendingtherefrom relative to a plurality of flow control devices and at leastone sensing device for extracorporeal blood processing. A mounting meansis employed for selectively, securably and supportably receiving thecassette member in a substantially fixed position relative thereto, andthe mounting means is selectively moveable between first and secondlocations wherein upon moving the mounting means from the first tosecond location, the tubing loops move into an operative position withcorresponding ones of the flow control devices and the cassette membermoves into a proper position for operation of the sensing means. In oneembodiment, the sensing means includes at least one pressure sensor formonitoring the fluid pressure within a blood removal passageway of thecassette member, and further includes ultrasonic sensors for monitoringthe fluid level of accumulated, uncollected blood components within areservoir of the cassette.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of an apheresis system;

FIGS. 2A-2B illustrate an extracorporeal tubing circuit and cassetteassembly thereof for the system of FIG. 1;

FIG. 3 is a front view of a pump/valve/sensor assembly for the system ofFIG. 1;

FIGS. 4A-4B are cross-sectional side views of first and second pressuresensing modules of the extracorporeal tubing circuit of FIGS. 2A-2Bcoupled with corresponding pressure sensors of the pump/valve/sensorassembly of FIG. 1;

FIG. 5 is a cross-sectional side view of the upper and lower ultrasoundsensors of the pump/valve/sensor assembly of FIG. 3 coupled with areservoir of the cassette assembly of the extracorporeal tubing circuitof FIGS. 2A-2B;

FIG. 6 is a cross-sectional side view of a platelet divert valvesubassembly of the pump/valve/sensor assembly of FIG. 3;

FIG. 7 is illustrates a loading assembly for a cassette mounting plateof the pump/valve/sensor assembly of FIG. 3;

FIG. 8 is an exploded, perspective view of the channel assembly from thesystem of FIG. 1;

FIGS. 9-9B is a top view of the channel housing from the channelassembly of FIG. 8 illustrating various dimensions;

FIG. 10 is a cross-sectional view taken along line 10--10 of FIG. 9;

FIG. 11A is a cutaway, perspective view of the platelet collect wellregion of the channel housing of FIG. 8;

FIG. 11B is a lateral cutaway view, looking upwardly of the plateletcollect well region of the channel housing of FIG. 8;

FIG. 12 is a cross-sectional view of the channel housing taken alongline 12--12 in FIG. 9;

FIG. 13 is a cross-sectional view of the channel housing taken alongline 13--13 in FIG. 9;

FIG. 14A is a top view of the blood inlet port slot, the RBC outletslot, and the control port slot on the channel housing of FIG. 8;

FIG. 14B is a cutaway, perspective view of the whole blood inlet portslot region of the channel housing of FIG. 8;

FIG. 14C is a cutaway, perspective view of the control port slot regionof the channel housing of FIG. 8;

FIG. 15 is a top view of the channel of FIG. 8 illustrating the ratio ofthe plasma volume to the red blood cell volume;

FIG. 16 is a perspective view of the blood processing vessel of thechannel assembly of FIG. 8 in a disassembled state;

FIG. 17 is a cross-sectional view of the blood processing vessel at theinterconnection;

FIG. 18 is cross-sectional view of the blood processing vessel takenalong lines 18--18 in FIG. 16;

FIG. 19A is a cutaway, perspective view of the blood inlet port assemblyfor the blood processing vessel of FIG. 8;

FIG. 19B is a longitudinal cross-sectional view of the blood inlet portassembly for the blood processing vessel of FIG. 8;

FIG. 19C is a cross-sectional view of the blood inlet port assemblyinterfacing with the blood processing vessel of FIG. 8;

FIG. 19D is a perspective view of the interior of the vane of the bloodinlet port of FIG. 19C;

FIG. 19E is a cutaway, perspective view of blood being introduced intothe blood processing vessel of FIG. 8 during an apheresis procedure;

FIG. 19F is a cross-sectional view of blood being introduced into theblood processing vessel and channel of FIG. 8 during an apheresisprocedure;

FIG. 19G is a cross-sectional view, looking downwardly, of blood beingintroduced into the blood processing vessel and channel of FIG. 8 duringan apheresis procedure;

FIG. 20A is a cutaway, perspective view of the red blood cell outletport assembly interfacing with the blood processing vessel of FIG. 8;

FIG. 20B is a longitudinal, cross-sectional view of the red blood celloutlet port assembly of FIG. 20A;

FIG. 20C is a cutaway, perspective view of the red blood cell portassembly interfacing with the blood processing vessel of FIG. 8 duringrinseback at the end of an apheresis procedure;

FIG. 20D is a cross-sectional view, looking downwardly, of the red bloodcell outlet port assembly interfacing with the blood processing vesselin the channel of FIG. 8 during rinseback at the end of an apheresisprocedure;

FIG. 21A is a cross-sectional view of the platelet outlet port assemblyfor the blood processing vessel of FIG. 8;

FIG. 21B is a plan view of the platelet outlet port assembly of FIG. 2Afrom the interior of the channel;

FIG. 22 is a cutaway, perspective view of the plasma port assembly forthe blood processing vessel of FIG. 8;

FIG. 23A is a cutaway, perspective view of the control port assembly forthe blood processing vessel of FIG. 8;

FIG. 23B is a cross-sectional view of the control port assemblyinterfacing with the blood processing vessel of FIG. 8;

FIG. 24 is a perspective view of the centrifuge rotor assembly for thesystem of FIG. 1;

FIG. 25A is a longitudinal cross-sectional view of the rotor assembly ofFIG. 24;

FIG. 25B is a top view of the rotor body of the rotor assembly of FIG.24;

FIG. 25C is a top view of the rotor body of the rotor assembly of FIG.24 with the upper counterweight removed so as to illustrate the lowercounterweight;

FIG. 25D is a front view of the rotor body of FIG. 24;

FIG. 25E is a perspective view of the left side of the blood processingvessel aperture in the rotor body of FIG. 24;

FIG. 25F is a cross-sectional view of the rotor body of FIG. 24;

FIG. 26 is a "master screen" for the computer graphics interface of theapheresis system of FIG. 1;

FIG. 27 is a "loading procedures screen" for the computer graphicsinterface of the apheresis system of FIG. 1;

FIG. 28 is one embodiment of a "help screen" for the loading proceduresscreen of FIG. 27;

FIG. 29 is a "disposable pressure test screen" for the computer graphicsinterface of the apheresis system of FIG. 1;

FIG. 30 is a "pressure test in progress screen" for the computergraphics interface of the apheresis system of FIG. 1;

FIG. 31 is a "AC interconnect screen" for the computer graphicsinterface of the apheresis system of FIG. 1;

FIG. 32 is the "master screen" of FIG. 26 which has been updated toreflect completion of the loading of the disposables;

FIG. 33 is a "donor/patient data screen" for the computer graphicsinterface of the apheresis system of FIG. 1;

FIG. 34 is a "weight input screen" for the computer graphics interfaceof the apheresis system of FIG. 1;

FIG. 35 is a "lab data screen" for the computer graphics interface ofthe apheresis system of FIG. 1;

FIG. 36 is the "master screen" of FIG. 26 which as been updated toreflect completion of the donor/patient preps;

FIG. 37 is a first "donor/patient preps screen" for the computergraphics interface of the apheresis system of FIG. 1;

FIG. 38 is a second "donor/patient preps screen" for the computergraphics interface of the apheresis system of FIG. 1;

FIG. 39 is a "run screen" for the computer graphics interface of theapheresis system of FIG. 1;

FIG. 40 is one embodiment of an "alarm screen" for the computer graphicsinterface of the apheresis system of FIG. 1;

FIG. 41 is a "supplemental alarm screen" for the alarm screen of FIG.40;

FIG. 42 is one embodiment of a "trouble shooting screen" for thecomputer graphics interface of the apheresis system of FIG. 1;

FIG. 43 is a "final run data display screen" for the computer graphicsinterface of the apheresis system of FIG. 1;

FIG. 44 is a "rinseback screen" for the computer graphics interface ofthe apheresis system of FIG. 1;

FIG. 45 is an "unload screen" for the computer graphics interface of theapheresis system of FIG. 1;

DETAILED DESCRIPTION

The present invention will be described in relation to the accompanyingdrawings which assist in illustrating the pertinent features thereof.Generally, all aspects of the present invention relate to improvementsin a blood apheresis system, both procedural and structural. However,certain of these improvements may be applicable to other extracorporealblood processing applications and such are within the scope of thepresent invention as well.

A blood apheresis system 2 is illustrated in FIG. 1 and allows for acontinuous blood component separation process. Generally, whole blood iswithdrawn from a donor/patient 4 and is provided to a blood componentseparation device 6 where the blood is separated into the variouscomponent types and at least one of these blood component types isremoved from the device 6. These blood components may then be providedfor subsequent use by another or may undergo a therapeutic treatment andbe returned to the donor/patient 4.

In the blood apheresis system 2, blood is withdrawn from thedonor/patient 4 and directed through a disposable set 8 which includesan extracorporeal tubing circuit 10 and a blood processing vessel 352and which defines a completely closed and sterile system. The disposableset 8 is mounted on the blood component separation device 6 whichincludes a pump/valve/sensor assembly 1000 for interfacing with theextracorporeal tubing circuit 10, and a channel assembly 200 forinterfacing with the disposable blood processing vessel 352.

The channel assembly 200 includes a channel housing 204 which isrotatably interconnected with a rotatable centrifuge rotor assembly 568which provides the centrifugal forces required to separate blood intoits various blood component types by centrifugation. The bloodprocessing vessel 352 is interfitted with the channel housing 204. Bloodthus flows from the donor/patient 4, through the extracorporeal tubingcircuit 10, and into the rotating blood processing vessel 352. The bloodwithin the blood processing vessel 352 is separated into various bloodcomponent types and at least one of these blood component types (e.g.,platelets, plasma, red blood cells) is continually removed from theblood processing vessel 352. Blood components which are not beingretained for collection or for therapeutic treatment (e.g., red bloodcells, white blood cells, plasma) are also removed from the bloodprocessing vessel 352 and returned to the donor/patient 4 via theextracorporeal tubing circuit 10.

Operation of the blood component separation device 6 is preferablycontrolled by one or more processors included therein, and mayadvantageously comprise a plurality of embedded personal computers toaccommodate interface with ever-increasing PC user facilities (e.g., CDROM, modem, audio, networking and other capabilities). Relatedly, inorder to assist the operator of the apheresis system 2 with variousaspects of its operation, the blood component separation device 6includes a graphical interface 660.

Disposable Set: Extracorporeal Tubing Circuit

As illustrated in FIGS. 2A-2B, blood-primable extracorporeal tubingcircuit 10 comprises a cassette assembly 110 and a number of tubingassemblies 20, 50, 60, 80, 90, 100 interconnected therewith. Generally,blood removal/return tubing assembly 20 provides a single needleinterface between a donor/patient 4 and cassette assembly 110, and bloodinlet/blood component tubing subassembly 60 provides the interfacebetween cassette assembly 110 and blood processing vessel 352. Ananticoagulant tubing assembly 50, platelet collection tubing assembly80, plasma collection tubing assembly 90, and vent bag tubingsubassembly 100 are also interconnected with cassette assembly 110. Aswill be appreciated, the extracorporeal tubing circuit 10 and bloodprocessing vessel 352 are interconnected to combinatively yield a closeddisposable for a single use.

The blood removal/return tubing assembly 20 includes a needlesubassembly 30 interconnected with blood removal tubing 22, blood returntubing 24 and anticoagulant tubing 26 via a common manifold 28. Theneedle subassembly 30 includes a needle 32 having a protective needlesleeve 34 and needle cap 36, and interconnect tubing 38 between needle32 and manifold 28. Needle subassembly 30 further includes a D sleeve 40and tubing clamp 42 positioned about the interconnect tubing 38. Bloodremoval tubing 22 may be provided with a Y-connector 44 interconnectedwith a blood sampling subassembly 46.

Cassette assembly 110 includes front and back molded plastic plates 112and 114 (see FIGS. 4A, 4B and 5) that are hot-welded together to definea rectangular cassette member 115 having integral fluid passageways. Thecassette assembly 110 further includes a number of outwardly extendingtubing loops interconnecting various integral passageways. The integralpassageways are also interconnected to the various tubing assemblies.

Specifically, cassette assembly 110 includes a first integralanticoagulant passageway 120a interconnected with the anticoagulanttubing 26 of the blood removal/return tubing assembly 20. The cassetteassembly 110 further includes a second integral anticoagulant passageway120b and a pump-engaging, anticoagulant tubing loop 122 between thefirst and second integral anticoagulant passageways 120a, 120b. Thesecond integral anticoagulant passageway 120b is interconnected withanticoagulant tubing assembly 50. The anticoagulant tubing assembly 50includes a spike drip chamber 52 connectable to an anticoagulant source,anticoagulant feed tubing 54 and a sterilizing filter 56. During use,the anticoagulant tubing assembly 50 supplies anticoagulant to the bloodremoved from a donor/patient 4 to reduce or prevent any clotting in theextracorporeal tubing circuit 10.

Cassette assembly 110 also includes a first integral blood inletpassageway 130a interconnected with blood removal tubing 22 of the bloodremoval/return tubing assembly 20. The cassette assembly 110 furtherincludes a second integral blood inlet passageway 130b and apump-engaging, blood inlet tubing loop 132 between the first and secondintegral blood inlet passageways 130a, 130b. The first integral bloodinlet passageway 130a includes a first pressure-sensing module 134 andinlet filter 136, and the second integral blood inlet passageway 130bincludes a second pressure-sensing module 138. The second integral bloodinlet passageway 130b is interconnected with blood inlet tubing 62 ofthe blood inlet/blood component tubing assembly 60.

Blood inlet tubing 62 is also interconnected with input port 392 ofblood processing vessel 352 to provide whole blood thereto forprocessing, as will be described. To return separated blood componentsto cassette assembly 110, the blood inlet/blood component tubingassembly 60 further includes red blood cell(RBC)/plasma outlet tubing64, platelet outlet tubing 66 and plasma outlet tubing 68 interconnectedwith corresponding outlet ports 492 and 520, 456, and 420 of bloodprocessing vessel 352. The RBC/plasma outlet tubing 64 includes aY-connector 70 to interconnect tubing spurs 64a and 64b. The blood inlettubing 62, RBC/plasma outlet tubing 64, plasma outlet tubing 68 andplatelet outlet tubing 66 all pass through first and second strainrelief members 72 and 74 and a braided bearing member 76 therebetween.This advantageously allows for a sealless interconnection, as taught inU.S. Pat. No. 4,425,112. As shown, multi-lumen connectors 78 can beemployed in the various tubing lines.

Platelet outlet tubing 66 of the blood input/blood component tubingassembly 60 includes a cuvette 65 for use in the detection of red bloodcells (via an interfacing RBC spillover detector provided on bloodcomponent separation device 6) and interconnects with a first integralplatelet passageway 140a of cassette assembly 110. As will beappreciated, a transparent member could alternatively be integrated intocassette assembly 110 in fluid communication with first integralplatelet passageway 140a to interface with an RBC spillover detector.

The cassette assembly 110 further includes a pump-engaging, platelettubing loop 142 interconnecting the first integral platelet passageway140a and a second integral platelet passageway 140b. The second integralplatelet passageway 140b includes first and second spurs 144a and 144b,respectively. The first spur 144a is interconnected with plateletcollection tubing assembly 80.

The platelet collection tubing assembly 80 can receive separatedplatelets during operation and includes platelet collector tubing 82 andplatelet collection bags 84 interconnected thereto via a Y-connector 86.Slide clamps 88 are provided on platelet collector tubing 82.

The second spur 144b of the second integral platelet passageway 140b isinterconnected with platelet return tubing loop 146 of the cassetteassembly 110 to return separated platelets to a donor/patient 4 (e.g.,upon detection of RBC spillover during platelet collection). For suchpurpose, platelet return tubing loop 146 is interconnected to the top ofa blood return reservoir 150 integrally formed by the molded front andback plates 112, 114 of cassette member 115. As will be furtherdescribed, one or more types of uncollected blood components,collectively referred to as return blood, will cyclically accumulate inand be removed from reservoir 150 during use. Back plate 114 of thecassette member 115 also includes an integral frame corner 116 defininga window 118 through a corner of cassette member 115. The frame corner116 includes keyhole recesses 119 for receiving and orienting theplatelet collector tubing 82 and platelet return tubing loop 146 in apredetermined spaced relationship within window 118.

The plasma outlet tubing 68 of blood inlet/blood component tubingassembly 60 interconnects with a first integral plasma passageway 160aof cassette assembly 110. Cassette assembly 110 further includes apump-engaging, plasma tubing loop 162 interconnecting the first integralplasma passageway 160a and a second integral plasma passageway 160b. Thesecond integral plasma passageway 160b includes first and second spurs164a and 164b. The first spur 164a is interconnected to the plasmacollection tubing assembly 90.

The plasma collection tubing assembly 90 may be employed to collectplasma during use and includes plasma collector tubing 92 and plasmacollection bag 94. A slide clamp 96 is provided on plasma collectortubing 92.

The second spur 164b of the second integral plasma passageway 160b isinterconnected to a plasma return tubing loop 166 to return plasma todonor/patient 4. For such purpose, the plasma return tubing loop 166 isinterconnected to the top of the blood return reservoir 150 of thecassette assembly 110. Again, keyhole recesses 119 in the frame 116 ofcassette assembly 110 are utilized to maintain the plasma collectortubing 92 and plasma return tubing loop 166 in a predetermined spacedrelationship within window 118.

The RBC/plasma outlet tubing 64 of the blood inlet/blood componenttubing assembly 60 is interconnected with integral RBC/plasma passageway170 of cassette assembly 110. The integral RBC/plasma passageway 170includes first and second spurs 170a and 170b, respectively. The firstspur 170a is interconnected with RBC/plasma return tubing loop 172 toreturn separated RBC/plasma to a donor/patient 4. For such purpose, theRBC/plasma return tubing loop 172 is interconnected to the top of bloodreturn reservoir 150 of the cassette assembly 110. The second spur 170bmay be closed off as shown, or may be connected with an RBC/plasmacollection tubing assembly (not shown) for collecting RBC/plasma duringuse. The RBC/plasma return tubing loop 172 (and RBC/plasma collectortubing if provided) is maintained in a desired orientation within window118 by keyhole recesses 119 of the frame 116.

Vent bag tubing assembly 100 is also interconnected to the top of bloodreturn reservoir 150 of cassette assembly 110. The vent bag tubingassembly 100 includes vent tubing 102 and a vent bag 104. During use,sterile air present since packaging within cassette assembly 110, andparticularly within blood return reservoir 150, cyclically passes intoand back out of vent tubing 102 and vent bag 104, as will be furtherdescribed.

Vent bag 94 may be provided with a sterile, gas pressure-relief valve ata top end (not shown). Further, it should be noted that, as opposed tovent bag tubing assembly 100, additional integral passageways,integrated chambers and tubing loops could be included in cassetteassembly 110 to perform the same functions as the vent bag tubingassembly 100.

The platelet return tubing loop 146, plasma return tubing loop 166 andRBC/plasma return tubing loop 172 are interconnected in a row to the topof blood return reservoir 150 immediately adjacent to forwardlyprojecting sidewalls 152 thereof so that the blood components returnedthereby will flow down the inner walls of the blood return reservoir150. The blood return reservoir 150 includes an enlarged, forwardlyprojecting mid-section 154, a reduced top section 156 and reduced bottomsection 158 (see also FIG. 5). A filter 180 is disposed in a bottomcylindrical outlet 182 of the blood return reservoir 150.

A first integral blood return passageway 190a is interconnected to theoutlet 182 of blood return reservoir 150, and is further interconnectedto a second integral blood return passageway 190b via a pump-engaging,blood return tubing loop 192. The second integral blood returnpassageway 190b is interconnected with the blood return tubing 24 of theblood removal/return tubing assembly 20 to return blood to thedonor/patient 4 via needle assembly 30.

As illustrated in FIGS. 2A-2B, pump-engaging tubing loops 122, 132, 142,162 and 192 extend from cassette member 115 to yield an asymmetricarrangement thereby facilitating proper mounting of cassette assembly110 on blood component separation device 6 for use. Relatedly, tofurther facilitate loading of cassette assembly 110, it is noted thatthe back plate 114 of cassette member 115 is preferably molded topresent a shallow pan-shaped back having a rim extending around theentire periphery and around window 118, the edge of the rim beingsubstantially coplanar with the back surface of the top, mid and bottomsections 154, 156, 158 of reservoir 150 and further defining a recessedregion within which first and second pressure sensing modules 134 and138 project.

Tubing assemblies 20, 50, 60, 80, 90 and 100 and cassette assembly 110preferably comprise PVC tubing and plastic components that permit visualobservation and monitoring of blood/blood components therewithin duringuse. Further, it should be noted that thin-walled PVC tubing (e.g., lessthan about 0.023 inch) may be advantageously employed for approved,sterile docking (i.e., the direct connection of two pieces of tubing)for platelet collector tubing 82 and plasma collector tubing 92 andRBC/plasma collector tubing, if provided. Thicker-walled PVC tubing(e.g., about 0.037 inch or more) is preferably utilized forpump-engaging tubing loops 132, 142, 162 and 192.

Pump/Valve/Sensor Assembly

As noted, cassette assembly 110 is mounted upon and operativelyinterfaces with the pump/valve/sensor assembly 1000 of blood componentseparation device 6 during use. The pump/valve/sensor assembly 1000 isangled upward at about 45° (see FIG. 1) and as illustrated in FIG. 3includes a cassette mounting plate 1010, and a number of peristalticpump assemblies, flow divert valve assemblies, pressure sensors andultrasonic level sensors interconnected to face plate 6a of bloodcollection device 6 for pumping, controlling and monitoring the flow ofblood/blood components through extracorporeal tubing circuit 10 duringuse.

More particularly, anticoagulant pump assembly 1020 is provided toreceive anticoagulant tubing loop 122, blood inlet pump assembly 1030 isprovided to receive blood inlet tubing loop 132, platelet pump assembly1040 is provided to receive platelet tubing loop 142, plasma pumpassembly 1060 is provided to receive plasma tubing loop 162, and bloodreturn pump assembly 1090 is provided to receive blood return tubingloop 192. Each of the peristaltic pump assemblies 1020, 1030, 1040,1060, and 1090 includes a rotor 1022, 1032, 1042, 1062 and 1092, andraceway 1024, 1034, 1044, 1064, and 1094 between which the correspondingtubing loop is positioned to control the passage and flow rate of thecorresponding fluid.

Platelet divert valve assembly 1100 is provided to receive plateletcollector tubing 82 and platelet return tubing loop 146, plasma divertvalve assembly 1110 is provided to receive plasma collector tubing 92and plasma return tubing loop 166, and RBC/plasma divert valve assembly1120 is provided to receive RBC/plasma return tubing loop 172 andRBC/plasma collector tubing if provided. As noted above, each pair oftubing for collection or return of separated blood components isdisposed in a predetermined spaced relationship within window 118 ofcassette assembly 110, thereby facilitating loading relative to thecorresponding divert value assemblies. As will be further described,platelet divert valve assembly 1100, plasma divert valve assembly 1110and RBC/plasma divert valve assembly 1120 each include a rotaryoccluding member 1400a, 1400b and 1400c that is selectively positionablebetween stationary occluding walls 1104 and 1106, 1114 and 1116, and1124 and 1126, respectively, for diverting fluid flow through one tubingof the corresponding pairs of tubings.

Pressure sensors 1200 and 1260 (See also FIGS. 4A and 4B) are providedwithin pump/valve/sensor assembly 1000 to operatively engage the firstand second pressure-sensing modules 134 and 138 of cassette assembly 110through openings 1120 and 1140 of cassette mounting plate 100.Similarly, ultrasonic level sensors 1300 and 1320 (see also FIG. 5) areprovided to operatively engage the blood return reservoir 150 cassetteassembly 110 through openings 1160 and 1180 of cassette mounting plate1100.

As shown in FIGS. 4A and B, the first and second pressure sensingmodules 134, 138 of cassette assembly 110 each comprise a circulardiaphragm 134a, 138a positioned on a raised cylindrical seat 134b, 138bformed into the back plate 114 of cassette assembly 110 with aring-shaped, plastic diaphragm retainer 134c, 138c hot-welded to theraised cylindrical seats 134b, 138b to establish a seal therebetween.This arrangement allows the diaphragms 134a, 138b to be directlyresponsive to the fluid pressures within the first and second integralblood inlet passageways 130a, 130b, respectively, and pressure sensors1200, 1260 to directly access the diaphragms 134a, 138a through thering-shaped retainers 134c, 138c. By monitoring the diaphragms 134a,138a, the pressure sensors 1200, 1260 can monitor the fluid pressurewithin the first and second integral blood inlet passageways 130a, 130b.In this regard, it should also be noted that since first integral bloodinlet passageway 130a is in direct fluid communication with bloodremoval tubing 22, and since blood removal tubing 22 and blood returntubing 24 are fluidly interconnected via the common manifold 28, thefirst pressure sensing module 134 will be responsive to and firstpressure sensor 1200 will actually sense the substantially commonpressure in both the blood removal tubing 22 and blood return tubing 24during operation.

With further regard to the first pressure sensing module 134 and firstpressure sensor 1200, FIG. 4A illustrates an air coupling arrangementthat allows for the sensing of positive and negative pressure changes(i.e., causing outward and inward flexure of diaphragm 134a). To achievean air seal between the first pressure sensor 1200 and first pressuresensing module 134, the sensor 1200 includes a resilient (e.g., rubber),cone-shaped engaging member 1202. The engaging member 1202 is attachedto an air channel member 1204 having a nipple-end 1206 that is receivedby beveled cylindrical extension 134d of retainer 134c. Air channelmember 1204 further includes an outer, annular projecting channelportion 1208 that contains an O-ring 1210 for sealed sliding engagementof the air channel member 1204 within housing 1212. As illustrated,housing 1212 includes ears 1214 which interface with a floatingpositioning member 1216 secured to the face plate 6a of blood componentseparation device 6. As shown, a slight clearance is provided in suchinterface so as to permit slight lateral movement of the engaging member1202 and air channel member 1204 during loading of the cassette assembly110. A threaded end 1218 of housing 1212 extends through the face plate6a of blood component separation device 6 and receives nut 1220thereupon, while leaving a slight clearance between the nut 1220 andface plate 6a. A spring 1222 is positioned within the housing 1212 andacts upon the annular channel portion 1208 of the air channel member1204 to provide a spring-loaded interface between the first pressuresensor 1200 and first pressure sensing module 134. Pressure sensingtransducer 1224 engages air channel member 1204 to sense positive andnegative pressure changes within sensing module 134 and provide anoutput signal in response thereto during use. As will be furtherdescribed, the output signal of pressure transducer 1224 can be employedto control the operation of blood inlet pump 1030 and blood return pump1090 during operation.

With regard to the second pressure sensing module 138 and the secondpressure sensor 1260, FIG. 4B illustrates a direct contact couplingapproach that allows for sensing of positive pressure changes (i.e.,causing outward flexure of diaphragm 138a). Such contact couplingfacilitates loading since the precise position of the diaphragm 138arelative to the second pressure sensor 1260 is not critical. As shown,second pressure sensor 1260 includes a projecting end portion 1262 thatis received by the ring retainer 138c of sensing module 138 to directlycontact diaphragm 138a. Pressure transducer 1264 is mounted relative tothe face plate 6a of the blood component separation device 6 via a ring1266 that threadingly engages a portion of pressure transducer 1264extending through the face plate 6a. Pressure transducer 1264 providesan output signal responsive to positive pressure changes acting upondiaphragm 138a.

As shown in FIG. 5, when cassette assembly 110 is mounted onpump/valve/sensor assembly 1000, the ultrasonic level sensors 1300 and1320 will be positioned to monitor the fluid level in the blood returnreservoir 150. More particularly, upper ultrasonic level sensor 1300will be positioned in contact with the reduced top section 156 of bloodreturn reservoir 150 and lower ultrasonic level sensor 1320 will bepositioned in contact with the reduced bottom section 158 of bloodreturn reservoir 150.

Ultrasonic sensors 1300, 1320 each comprise pulse/echo transducers 1302,1322 having a contact surface (e.g., urethane) 1304, 1324 thatfacilitates divert dry coupling (i.e., without a gel or other likecoupling medium) with the blood return reservoir 150. By way of example,ultrasonic sensors may comprise model Z-11405 transducers offered byZerex Inc. of 5175 Greenpine Drive, Salt Lake City, Utah. Pulse/echotransducers 1302, 1322 are disposed within housings 1306, 1326 forinterconnection with face plate 6a of the blood component separationdevice 6. Housings 1306, 1326 include a flange 1308, 1328 for engagingthe front of face plate 6a, and further include a threaded end 1308,1328 that extends through the face plate 6a to receive correspondingretaining nuts 1310, 1330. A slight clearance is provided for betweenflanges 1308, 1328 and face plate 6a. Springs 1312, 1332 are positionedwithin housings 1306, 1326 to act upon the corresponding pulse/echotransducers 1302, 1332 via E-clips 1314, 1334 disposed therebetween.Such spring loading of pulse/echo transducers 1302, 1332 yields apredetermined desired loading pressure for pulse/echo transducers 1302,1332 relative to reservoir 150 during operation (e.g., at least about 5lbs.). O-rings 1316, 1336 are provided intermediate pulse/echotransducers 1302, 1322 and housings 1306, 1326 to provide a sliding sealtherebetween. Cables 1318, 1338 are interconnected to transducers 1302,1322 to provide pulsing signals and return detected echo signals.

By gauging the presence and timing of return ultrasonic echo pulses eachof sensors 1300 and 1320 can be employed to monitor the presence orabsence of fluid within their corresponding echo regions within theblood return reservoir 150, and permit blood component separation device6 to provide pump control signals in response thereto. Moreparticularly, when return blood accumulates up into the echo region ofupper level sensor 1300 during blood processing, ultrasonic pulsesemitted by upper level sensor 1300 will readily pass through the returnblood and reflect off of the opposing reservoir outside sidewall/airinterface to yield echo pulses having a predetermined minimum strengththat are detected by upper sensor 1300 within a predetermined timeperiod after transmission. When such echo pulses are received, uppersensor 1300 provides a signal that is used by blood component separationdevice 6 to initiate operation of blood return pump 1090 so as to removeaccumulated return blood from the blood return reservoir 150 andtransfer the same to the donor/patient 4.

When blood return pump 1090 has removed return blood from the reservoir150 down into the lower echo region, ultrasonic pulses emitted by lowerlevel sensor 1320 will not be reflected at the opposing reservoiroutside sidewall/air interface to yield echo pulses having apredetermined minimum strength for detection by lower level sensor 1320within a predetermined time period after transmission. When this occurs,lower level sensor 1320 will fail to provide corresponding signals toblood component separation device 6, and blood component separationdevice 6 will automatically stop blood return pump 1090 to stop furtherremoval of return blood from the blood return reservoir 150, and returnblood will again begin accumulating in reservoir 150. Thus, in the bloodprocessing mode, blood component separation device 6 will not initiateoperation of blood return pump 1090 unless and until it receives signalsfrom upper ultrasonic sensor 1300 (the provisions of such signalsindicating the presence of return blood in the upper echo region), andwill thereafter automatically stop operation of blood return pump 1090if it fails to receive signals from ultrasonic sensor 1320 (the failureto receive such signals indicating the absence of return blood in thelower echo region).

In an initial blood prime mode, whole blood is introduced to reservoir150 from a donor/patient 4 through blood return tubing 24, integralpassageways 190a, 190b, and tubing loop 192 via reverse operation ofblood return pump 1090. When such whole blood accumulates up into theecho region of lower level sensor 1320, ultrasonic pulses emitted bylower level sensor 1320 will pass through the blood and reflect off ofthe opposing reservoir outside sidewall/air interface to yield echopulses having a predetermined minimum strength that are detected bylower level sensor 1320 within a predetermined time period aftertransmission. When such echo pulses are received in the blood primemode, lower level sensor 1320 provides a signal that is used by bloodcomponent separation device 6 to turn off blood return pump 1090 and endthe blood prime mode. Blood component separation device 6 then initiatesthe blood processing mode.

It is contemplated that ultrasonic sensors 1300, 1320 can be utilizedfor indicating and/or confirming the desired mounting relationship ofcassette member 15 on cassette mounting plate 1010 for blood processingoperations. For such purposes, if the desired mounting has beenachieved, the sensors 1300, 1320 should be coupled to reservoir 150 sothat ultrasonic pulses reflect off the interface between the insidesurface of the back sidewall of reservoir 150 (i.e., the sidewallcontacted by the sensors 1300, 1320) and contained air within reservoir150, and be received with a predetermined minimum strength within apredetermined time period after transmission. If such echo pulses arereceived with respect to both ultrasonic sensors 1300, 1320, the desiredloading relationship will be indicated and/or confirmed. Further, it isnoted that ultrasonic sensors 1300, 1320 may be employable to sense echopulses from the interfaces between fluid contained within the reservoir150 and the inside surface of the outer sidewall of reservoir 150 in theupper and lower echo regions of the reservoir during operation. If suchecho pulses are detectible within corresponding, predetermined timewindows, corresponding signals provided by ultrasonic sensors 1300, 1320can provide a further input for blood component separation device 6 tocontrol operation of blood return pump 1090.

It should be noted that in the illustrated arrangement, the upper andlower ultrasonic sensors 1300 and 1320 advantageously operate viacoupling with reduced cross-sectional portions 156 and 158 of reservoir150. The reduced upper and lower reservoir portions 15, 158, accommodatereliable detection of echo pulses when fluid is present in the upper andlower echo regions, and the enlarged mid-portion 158 providessatisfactory return blood holding capabilities. FIG. 6 shows thecomponents of each of the platelet divert valve subassembly 1100, plasmadivert valve subassembly 1100 and RBC/plasma divert valve subassembly1120. Each subassembly includes a rotary occluder member 1400 having aheaded shaft member 1402 and barrel sleeve 1404 positioned thereupon androtatable relative thereto. The subassembly further comprises a mainvalve shaft 1406 positioned within a valve body 1408 that is secured toface plate 6a of blood component separation device 6. An O-ring 1410 isprovided in a recess on the main valve shaft 1406 to provide a slidingseal between main valve shaft 1406 and extensions 1412 of main valvebody 1408. The main valve shaft 1406 is driven by a motor 1414 mountedon mount plate 1416 that in turn is mounted to and set off from faceplate 6a by standoff legs 1418.

For positioning rotary occluder member 1400 for occlusion relative toone of the co-acting walls (e.g. 1104 or 1106 of the plasma divert valvesubassembly 1100) or for loading/removal of the cassette assembly 110 onthe blood component separation device 6, each divert valve subassemblycomprises three optical through-beam sensors 1420 (two shown)interconnected to standoff legs 1418 via support layer 1419, and anoptical interrupter member 1422 interconnected to the main valve shaft1406. Each through-beam sensor 1420 is of a U-shape configuration with aradiation source and radiation receiver disposed on opposing legs. Theoptical interrupter member 1422 has an inverted cup configuration withits sidewalls interposed and rotatable between the opposing legs ofsensors 1420. The optical interrupter member 1422 includes a singlewindow 1424 therethrough. As will be appreciated, the position of therotary occluder member 1400 relative to the window 1424 of the opticalinterrupter 1422 is known, such that when the optical window 1424 passesbetween the opposing radiation source/receiver for a given opticalsensor 1420, the optical sensor 1420 will provide a signal in responseto the through-beam (indicating the position of the rotary occludermember 1400), and the signal is employed to control the operation ofmotor 1414 to dispose rotary occluder member 1400 in the desiredposition. To provide/route such signals, the support layer 1419 mayadvantageously comprise a printed circuit board. Optical sensors 1420are preferably positioned slightly "upstream" of predetermined stopregions for occlusion or cassette loading so that motor 1414 will beable to dynamically slow down and position rotary occluder member 1400within such regions as desired. To insure the desired positioning forocclusion, however, stops 1426 are provided on main valve shaft 1406 toco-act with cross-pin 1428 interconnected to main valve shaft 1406 toinsure stop positioning of rotary occluder member 1400 relative to thedesired occluding wall.

Each of the occluding walls 1104 and 1106, 1114 and 1116, and 1124 and1126, are provided with arcuate recesses (not shown) for receiving therotatable barrel sleeve on 1404 of rotary occluder members 1400a, 1400band 1400c. By way of example, such arcuate recesses may have an arclength of 20° and provide a tolerance range for positioning the rotaryoccluder members 1400a, 1400b, 1400c to achieve the desired tubingocclusion. As illustrated in FIG. 3, occluding wall 1106 may be providedwith a resilient pad to best accommodate the use of approved,sterile-docking tubing for platelet collector tubing 82. Further, and asnoted above, sterile-docking tubing may be advantageously employed forplasma collector tubing 92 and, if provided, RBC/plasma collector tubing(not shown), and corresponding resilient pads (not shown) may beprovided on occluding walls 1114 and 1124. In this regard, given thethinness and relatively high-spring rate of sterile-docking tubing, theuse of resilient pads in connection therewith increases the wearabilityof the sterile docking tubing.

In order to establish an initial predetermined set position of thecassette assembly 110 relative to the pump/valve/sensor assembly 1000,the cassette assembly 110 includes downwardly extending cornerpositioning tabs 15 and top and bottom edge lips 17 that engagecorresponding lower channel projections 1102a on cassette mounting plate1010 and upper channel projections 1102b on a pivotable spring-loadedinterlock member 1104 that extends across the top edge of cassettemounting plate 1010. The interlock member 1104 is spring-loaded topositively engage cassette assembly 110 upon loading via a springpositioned within housing 1106, and is provided with a tab 1108 forpivotable movement during cassette loading against the spring loadingpressure. Preferably, interlock member 1104 is disposed relative to theraceway 1094 of return pump assembly 1090, such that when cassetteassembly 110 is fully loaded for operation on blood component separationdevice 6, raceway 1094 will physically restrict interlock member 1104from being pivoted, thereby advantageously restricting removal and/ormovement of cassette assembly 110 during use.

After cassette assembly 110 has been secured on the cassette mountingplate 1010, a loading assembly 1500 retracts the cassette mounting plate1010 towards face plate 6a of the blood component separation device 6 toestablish the above-noted, fully-loaded pump, valve and sensorrelationships. As illustrated in FIG. 7, loading assembly 1500 includestwo posts 1502 upon which cassette mounting plate 1010 is supportablyinterconnected. The posts 1502 extend through the face plate 6a of bloodcollection device 6a and are interconnected to a cross-connect member1504. A drive nut 1506 is secured to cross-connect member 1504 andengages a drive screw 1508. The drive screw 1508 is in turn rotatablyinterconnected to a drive motor 1510 via coupling 1512, the drive motor1510 being mounted on a platform 1514 which is supportivelyinterconnected to face plate 6a via standoff legs 1516. The drive motor1510 operates to turn drive screw 1508 so as to cause cross-connectmember 1504 and posts 1502 to selectively move cassette mounting plate1010 perpendicularly towards face plate 6a during loading procedures andperpendicularly away from face plate 6a for unloading of the cassetteassembly 110.

To establish the desired position of cassette mounting plate 1010,U-shaped optical through-beam sensors 1520a and 1520b are mounted onpost bearing holders 1522 and an optical occluder member 1524 having awindow 1526 is interconnected to the cross-connect member 1504. Each ofthe U-shaped optical sensors 1520a, 1520b includes a radiation sourceand radiation receiver positioned on opposing extending legs, and theoptical occluder member 1524 extends between such legs. Since therelative positions between cassette mounting plate 1010 and opticalsensors 1520a, 1520b are known, by detecting the passage of radiationthrough window 1526 using optical sensors 1520, and providing a signalresponsive thereto,the position of cassette mounting plate 1010 forloading and unloading can be automatically established. For example,when a throughbeam is received by optical sensor 1520b, a signal will beprovided to stop motor 1510 in a position wherein cassette assembly 110will be fully loaded on the pump/valve/sensor assembly 1000 foroperation.

To confirm such loaded condition, first and second pressure sensors 1200and 1260 and upper and lower ultrasonic sensors 1300 and 1320 may beemployed. For example, predetermined minimum pressure values can beestablished and actual pressures measured for each of the first andsecond pressure sensors 1200 and 1260 to confirm the desired loading ofcassette assembly 110. Further, and of particular interest, ultrasonicsensors 1300 and 1320 can be advantageously employed to confirm thedesired loading, since upon proper coupling to reservoir 150 echo pulsesshould be reflected off of the internal sidewall/air interface with apredetermined minimum strength within a predetermined time period asnoted above.

It should be noted that drive motor 1510 preferably includes a number ofreduction gears with the last gear being operatively associated with aslip clutch plate to limit the maximum amount of force that may beapplied by cassette mounting plate 1010 (e.g., to an object betweencassette mounting plate 1010 and face plate 6a). Relatedly, it ispreferable to include control capabilities wherein during a load cycleif the window 1526 of optical occluder 1524 has not moved from itsposition within the first optical pass through sensor 1520a to aposition within the second optical pass through sensor 1520b within apredetermined time period, drive motor 1510 will automatically eitherstop or reverse operations

To summarize the loading process, loading assembly 1500 initiallydisposes cassette mounting plate 1010 in an extended position. With thecassette mounting plate 1010 in such extended position, interlock member1104 is pivoted away from cassette mounting plate 1010 and cassetteassembly 110 is positioned on cassette mounting plate 1010 with bottomedge lips 17 of cassette assembly 110 being received by lower channelprojections 1102a of cassette mounting plate 1010 and, upon returnpivotal movement of interlock member 1104, top edge lips 17 of cassetteassembly 110 being engaged by upper channel projections 1102b oninterlock member 1104. Loading assembly 1500 is then operated to retractcassette mounting plate 1010 from its extended position to a retractedposition, wherein tubing loops 122, 132, 162, 142, 192 of cassetteassembly 110 are automatically positioned within the correspondingperistaltic pump assemblies 1020, 1030, 1060, 1040 and 1090. For suchpurposes, the rotors of each of the peristaltic pump assemblies are alsooperated to achieve loaded positioning of the corresponding tubingloops. Further, it should be noted that for loading purposes, the rotaryoccluder members 1400a, 1400b and 1400c of the divert valve assemblies1100, 1110 and 1120 are each positioned in an intermediate position soas to permit the corresponding sets of tubing to be positioned on eachside thereof.

Upon retraction of the cassette mounting plate 1010, spring-loaded,ultrasonic sensors 1300 and 1320 will automatically be coupled toreservoir 150 and first and second pressure sensors 1200 and 1260 willautomatically couple to first and second pressure sensing modules 134and 138 of cassette assembly 110. In this fully-loaded, retractedposition, the cassette assembly 110 will be restricted from movement orremoval by the above-noted physical restriction to pivotal movement ofinterlock member 1104 provided by raceway 1094 of return pump assembly1090.

It is also noted that during loading of cassette assembly 110 on theblood component separation device 6, cuvette 65 is positioned within anRBC spillover detector 1600 (e.g., an optical sensor for detecting thepresence of any red blood cells in the separated platelet fluid streamand providing a signal response thereto) provided on the face plate 6a.Similarly, a portion of anticoagulant tubing 54 is positioned within anAC sensor 1700 (e.g., an ultrasonic sensor for confirming the presenceof anticoagulant and providing a signal in the absence thereof) alsoprovided in face plate 6a.

To unload cassette assembly 110 after use, the occluding members 1400a,1400b and 1400c of each divert value assembly are again positioned in anintermediate position between the corresponding occluding walls andloading assembly 1500 is operated to move cassette mounting plate 1010from its retracted position to its extended position. Contemporaneously,the rotors of the various peristaltic pump assemblies are operated topermit the corresponding tubing loops to exit the same. In the extendedposition, the interlock member 1104 is pivoted out of engagement withcassette assembly 110 and cassette assembly 110 is removed and disposedof.

Operation of Extracorporeal Tubing Circuit and Pump/Valve/SensorAssembly

In an initial blood prime mode of operation, blood return pump 1090 isoperated in reverse to transfer whole blood through blood removal/returntubing assembly 20, integral blood return passageway 190, blood returntubing loop 192 and into reservoir 150. Contemporaneously and/or priorto the reverse operation of blood return pump 1090, anticoagulantperistaltic pump 1020 is operated to prime and otherwise provideanticoagulant from anticoagulant tubing assembly 50, throughanticoagulant integral passageway 120, and into blood removal tubing 22and blood return tubing 24 via manifold 28. When lower level ultrasonicsensor 1320 senses the presence of the whole blood in reservoir 150 asignal is provided and blood component separation device 6 stops bloodreturn peristaltic pump 1090. As will be the blood prime mode being theblood prime mode blood inlet pump 1030 is also operated to transferblood into blood inlet integral passageway 130, through blood inlettubing loop 132 and into blood inlet/blood component tubing assembly 60to prime the blood processing vessel 352.

During the blood prime mode, vent bag assembly 100 receives air fromreservoir 150. Relatedly, the occluding members 1400a, 1400b, 1400c ofdivert assemblies 1100, 1110, 1120 are each preferably positioned todivert flow to the reservoir 150. It should also be noted that tofacilitate blood priming, the cassette assembly 110 is angled upward atabout 45° in its loaded position, and the integral passageways ofcassette member 115 are disposed so that all blood and blood componentinlet paths provide for a bottom-to-top plug flow.

In the blood processing mode, the blood inlet peristaltic pump 1030,platelet peristaltic pump 1040 and plasma peristaltic pump 1060 areoperated continuously, and the occluding members 1400a, 1400b, 1400c arepositioned for collection or return of corresponding blood components,as desired. During a blood removal submode, blood return peristalticpump 1090 is not operated so that whole blood will pass into bloodremoval/return tubing assembly 20 and transferred to processing vessel352 via the cassette assembly 110 and blood inlet/blood component tubingassembly 60. In the blood removal submode, uncollected blood componentsare transferred from the processing vessel 352 to cassette assembly 110,and uncollected components are passed into and accumulate in reservoir150 up to a predetermined level at which upper level ultrasonic sensor1300 provides signals used by blood component separation device 6 to endthe blood removal submode and initiate a blood return submode. Moreparticularly, blood return submode is initiated by forward operation ofblood return peristaltic pump 1090. In this regard, it should beappreciated that in the blood return submode the volume transfer rate ofreturn blood through blood return tubing loop 192 utilizing blood returnperistaltic pump 1090 is established by blood component separationdevice 6, according to a predetermined protocol, to be greater than thevolume transfer rate through blood inlet tubing loop 132 utilizing bloodinlet peristaltic pump 1030. As such, the accumulated blood in reservoir150 is transferred into the blood return tubing of blood removal/returntubing assembly 20 and back into the donor/patient 4. During the bloodprocessing mode, when the accumulated return blood in reservoir 150 isremoved down to a predetermined level, lower level ultrasonic sensor1320 will fail to provide signals to blood component separation device6, whereupon blood component separation device 6 will automatically stopblood return peristaltic pump 1090 to end the blood return submode. Thisautomatically serves to reinitiate the blood removal submode since bloodinlet peristaltic pump 1030 continuously operates.

During the blood processing mode, pressure sensor 1200 sensesnegative/positive pressure changes within the blood removal tubing 22blood return tubing 26, via first integral blood inlet passageway 130a.Such monitored pressure changes are communicated to blood componentseparation device 6 which in turn controls blood inlet pump 1030 andreturn pump 1090 so as to maintain fluid pressures within predeterminedranges during the blood removal and the blood return submodes.Specifically during the blood removal submode, if a negative pressure issensed that exceeds (i.e., is less than) a predetermined negative limitvalue, then blood component separation device 6 will slow down operationof blood inlet pump 1030 until the sensed negative pressure is backwithin an acceptable range. During the blood return submode, if apositive pressure is sensed that exceeds (i.e., is greater than) apredetermined positive limit value, then blood component separationdevice 6 will slow down operation of blood return pump 1090 until thesensed positive pressure is back within an acceptable range.

Pressure sensor 1260 monitors the positive pressure within the secondintegral blood inlet passageway 130b and blood inlet tubing 62. If suchsensed positive pressure exceeds a predetermined maximum value, bloodcomponent separation device 6 will initiate appropriate responsiveaction, including, for example, slowing or stoppage of the centrifugeand peristaltic pumps.

During the blood processing mode, blood component separation device 6controls the operation of anticoagulant pump 1020 according to apredetermined protocol and responsive to signals provided by AC sensor1700 (e.g., indicating a depleted anticoagulant source). Also, bloodcomponent separation device 6 also controls the operation of divertassemblies 1100, 1110, 1120 according to predetermined instructions andfurther pursuant to any detect signals provided by RBC spilloverdetector 1600. In the latter regard, if an RBC spillover in theseparated platelet stream is detected, blood component separation device6 will automatically cause occluder member 1400a to divert the separatedplatelet stream to the return reservoir 150 until the RBC spillover hascleared, thereby keeping red blood cells from undesirably passing intoplatelet collector tubing assembly 80.

In normal operation, whole blood will pass through needle assembly 30,blood removal tubing 22, cassette assembly 110 and blood inlet tubing 62to processing vessel 352. As will be further described in detail, thewhole blood will then be separated in vessel 352. A platelet stream willpass out of port 420 of the vessel, through platelet tubing 66, backthrough cassette assembly 110, and will then be either collected incollector assembly 80 or diverted to reservoir 150. Similarly, separatedplasma will exist vessel 352 through port 456 to plasma tubing 68 backthrough cassette assembly 110, and will then either be collected inplatelet tubing assembly 90 or diverted to reservoir 150. Further, redblood cells and plasma (and potentially white blood cells) will passthrough ports 492 and 520 of vessel 352 through RBC/plasma tubing 64,through cassette assembly 110 and into reservoir 150. In this regard, itis contemplated that second spur 170b of integral passageway 170 may beconnected to a separate RBC/plasma collector tubing assembly (not shown)and RBC/plasma divert valve assembly 1120 could be operated for thecollection of RBC/plasma.

As noted above, when uncollected platelets, plasma, and RBC/plasma (andpotentially white blood cells) have accumulated in reservoir 150 up toupper ultrasonic level sensor 1300, operation of return peristaltic pump1090 will be initiated to remove the noted components from reservoir 150and transfer the same back to the donor/patient 4 via the return tubing24 and needle assembly 20. When the fluid level in the reservoir 150drops down to the level of the lower ultrasonic level sensor 1320, thereturn peristaltic pump 1090 will automatically turn off reinitating theblood removal submode. The cycle between blood removal and blood returnsubmodes will then continue until a predetermined amount of platelets orother collected blood components have been harvested.

In one embodiment, reservoir 150 and upper and lower ultrasonic sensors1300 and 1320 are provided so that, during the blood processing mode,approximately 50 milliliters of return blood will be removed fromreservoir 150 during each blood return submode and accumulated duringeach blood removal submode. Relatedly, in such embodiment, lower andupper level triggering by ultrasonic sensors 1300 and 1320 occurs atfluid volumes of about 15 milliliters and 65 milliliters, respectively,within reservoir 150. For such embodiment, it is also believed desirableto provide for a volume transfer operating rate range of about 30 to 300milliliters/minute through blood return tubing loop 192 utilizing returnpump 1090, and a volume transfer operating rate range of about 20 to 140milliliters/minute through blood inlet tubing loop 132 utilizing inletpump 1030. Additionally, for such embodiment a negative pressure limitof about -250 mmHg and positive pressure limit of about 350 mmHg isbelieved appropriate for controlling the speed of inlet pump 1030 andreturn pump 1090, respectively, in response to the pressures sensed infirst pressure sensing module 134. A positive pressure limit of about1350 mmHg within second sensing module 138 is believed appropriate fortriggering slow-down or stoppage of the centrifuge and pumps.

Channel Housing

The channel assembly 200 is illustrated in FIGS. 8-23B and includes achannel housing 204 which is disposed on the rotatable centrifuge rotorassembly 568 (FIGS. 1 and 24) and which receives a disposable bloodprocessing vessel 352. Referring more specifically to FIGS. 8-15, thechannel housing 204 has a generally cylindrically shaped perimeter 206with a diameter of preferably no more than about 10 inches to achieve adesired size for the blood component separation device 6 (e.g., toenhance its portability). An opening 328 extends longitudinally throughthe channel housing 204 and contains an axis 324 about which the channelhousing 204 rotates. The channel housing 204 may be formed frommaterials such as delrin, polycarbonate, or cast aluminum and mayinclude various cut-outs or additions to achieve weight reductionsand/or rotational balance.

The primary function of the channel housing 204 is to provide a mountingfor the blood processing vessel 352 such that the blood may be separatedinto the blood component types in a desired manner. In this regard, thechannel housing 204 includes a generally concave channel 208 in whichthe blood processing vessel 352 is positioned. The channel 208 isprincipally defined by an inner channel wall 212, an outer channel wall216 which is radially spaced from the inner channel wall 212, and achannel base 220 which is positioned therebetween. The channel 208 alsoextends from a first end 284 generally curvilinearly about a rotationalaxis 324 of the channel housing 204 to a second end 288 which overlapswith the first end 284 such that a continuous flow path is providedabout the rotational axis 324. That is, the angular disposition betweenthe first end 284 of the channel 208 and the second end 288 of thechannel 208 is greater than 360° and up to about 390° and in theillustrated embodiment is about 380°. Referring to FIG. 15, this angulardisposition is measured by the angle β, along a constant radius arc,between a first reference ray 336 which extends from the rotational axis324 to the first end 284, and a second reference ray 340 which extendsfrom the rotational axis 324 to the second end 288 of the channel 208.

The blood processing channel vessel 352 is disposed within the channel208. Generally, the channel 208 desirably allows blood to be provided tothe blood processing vessel 352 during rotation of the channel housing204, to be separated into its various blood component types bycentrifugation, and to have various blood component types removed fromthe blood processing vessel 352 during rotation of the channel housing204. For instance, the channel 208 is configured to allow for the use ofhigh packing factors (e.g., generally a value reflective of how "tightlypacked" the red blood cells and other blood component types are duringcentrifugation and as will be discussed in more detail below). Moreover,the channel 208 also desirably interacts with the blood processingvessel 352 during centrifugation (e.g., by retaining the bloodprocessing vessel 352 in the channel 208 and by maintaining a desiredcontour of the blood processing vessel 352). In addition, the channel208 allows for a blood priming of the blood processing vessel 352 (i.e.,using blood as the first liquid which is provided to the bloodprocessing vessel 352 in an apheresis procedure).

The above-identified attributes of the channel 208 are providedprimarily by its configuration. In this regard, the channel housing 204includes a blood inlet slot 224 which is generally concave and whichintersects the channel 208 at its inner channel wall 212 insubstantially perpendicular fashion (e.g., the blood inlet slot 224interfaces with the inner channel wall 212). A blood inlet port assembly388 to the interior of the blood processing vessel 352 is disposed inthis blood inlet slot 224 such that blood from the donor/patient 4 maybe provided to the blood processing vessel 352 when in the channel 208.In order to retain a substantially continuous surface along the innerchannel wall 212 during an apheresis procedure and with the bloodprocessing vessel 352 being pressurized, namely by reducing thepotential for the blood inlet port assembly 388 deflecting radiallyinwardly within the blood inlet slot 224, a recess 228 is disposed onthe inner channel wall 212 and contains the end of the blood inlet slot224 (e.g., FIG. 14A). This recess 228 receives a shield 408 which isdisposed about the blood inlet port assembly 388 on the exterior surfaceof the blood processing vessel 352 as will be discussed in more detailbelow.

As illustrated in FIGS. 8-9, an RBC dam 232 of the channel 208 isdisposed in a clockwise direction from the blood inlet slot 224 andwhose function is to preclude RBCs and other large cells such as WBCsfrom flowing in a clockwise direction beyond the RBC dam 232. Generally,the surface of the RBC dam 232 which interfaces with the fluidcontaining volume of the blood processing vessel 352 may be defined as asubstantially planar surface or as an edge adjacent the collect well236. At least in that portion of the channel 208 between the blood inletport 224 and the RBC dam 232, blood is separated into a plurality oflayers of blood component types including, from the radially outermostlayer to the radially innermost layer, red blood cells ("RBCs"), whiteblood cells ("WBCs"), platelets, and plasma. The majority of theseparated RBCs are removed from the channel 208 through an RBC outletport assembly 516 which is disposed in an RBC outlet slot 272 associatedwith the channel 208, although at least some RBCs may be removed fromthe channel 208 through a control port assembly 488 which is disposed ina control port slot 264 associated with the channel 208.

The RBC outlet port slot 272 is disposed in a counterclockwise directionfrom the blood inlet slot 224, is generally concave, and intersects thechannel 208 at its inner channel wall 212 in substantially perpendicularfashion (e.g., the RBC outlet slot 272 interfaces with the inner channelwall 212). An RBC outlet port assembly 516 to the interior of the bloodprocessing vessel 352 is disposed in this RBC outlet slot 272 such thatseparated RBCs from the apheresis procedure may be continually removedfrom the blood processing vessel 352 when in the channel 208 (e.g.,during rotation of the channel housing 204). In order to retain asubstantially continuous surface along the inner channel wall 212 duringan apheresis procedure and with the blood processing vessel 352 beingpressurized, namely by reducing the potential for the RBC outlet portassembly 516 deflecting radially inwardly within the RBC outlet slot272, a recess 276 is disposed on the inner channel wall 212 and containsthe end of the RBC outlet slot 272 (e.g., FIGS. 14A, 14B). This recess276 receives a shield 538 which is disposed about the RBC outlet portassembly 516 on the exterior surface of the blood processing vessel 352as will be discussed in more detail below.

The control port slot 264 is disposed in a counterclockwise directionfrom the RBC outlet slot 272, is generally concave, and intersects thechannel 208 at its inner channel wall 212 in substantially perpendicularfashion (e.g., the control port slot 264 interfaces with the innerchannel wall 212). A control port assembly 488 to the interior of theblood processing vessel 352 is disposed in the control port slot 264(e.g., FIGS. 14A and C). In order to retain a substantially continuoussurface along the inner channel wall 212 during an apheresis procedureand with the blood processing vessel 352 being pressurized, namely byreducing the potential for the control port assembly 488 deflectingradially inwardly within the control port slot 264, a recess 268 isdisposed on the inner channel wall 212 and contains the end of thecontrol port slot 264. This recess 268 receives a shield 508 which isdisposed about the control port assembly 488 on the exterior surface ofthe blood processing vessel 352 as will be discussed in more detailbelow.

The portion of the channel 208 extending between the control port slot264 and the RBC dam 232 may be characterized as the first stage 312 ofthe channel 208. The first stage 312 is configured to remove primarilyRBCs from the channel 208 by utilizing a reverse flow in relation to theflow of platelet-rich plasma through the channel 208 which is in aclockwise direction. In this regard, the outer channel wall 216 extendsalong a curvilinear path from the RBC dam 232 to the blood inlet slot224 generally progressing outwardly away from the rotational axis 324 ofthe channel housing 204. That is, the radial disposition of the outerchannel wall 216 at the RBC dam 232 is less than the radial dispositionof the outer channel wall 216 at the blood inlet slot 224. The portionof the RBC outlet slot 272 interfacing with the channel 208 is alsodisposed more radially outwardly than the portion of the blood inletslot 224 which interfaces with the channel 208.

In the first stage 312, blood is again separated into a plurality oflayers of blood component types including, from the radially outermostlayer to the radially inner most layer, red blood cells ("RBCs"), whiteblood cells ("WBCs"), platelets, and plasma. As such, the RBCs sedimentagainst the outer channel wall 216 in the first stage 312. Byconfiguring the RBC dam 232 such that it is a section of the channel 210which extends further inwardly toward the rotational axis 324 of thechannel housing 204, this allows the RBC dam 232 to retain separatedRBCs and other large cells as noted within the first stage 312. That is,the RBC dam 232 functions to preclude RBCs from flowing in a clockwisedirection beyond the RBC dam 232.

Separated RBCs and other large cells as noted are removed from the firststage 312 utilizing the above-noted configuration of the outer channelwall 216 which induces the RBCs and other large cells as noted to flowin a counterclockwise direction (e.g., generally opposite to the flow ofblood through the first stage 312). Specifically, separated RBCs andother large cells as noted flow through the first stage 312 along theouter channel wall 216, past the blood inlet slot 224 and thecorresponding blood inlet port assembly 388 on the blood processingvessel 352, and to an RBC outlet slot 272. In order to reduce thepotential for counterclockwise flows other than separated RBCs beingprovided to the control port assembly 488 disposed in the control portslot 264 (e.g., such that there is a sharp demarcation or interfacebetween RBCs and plasma proximate the control port slot 264 as will bediscussed in more detail below), a control port dam 280 of the channel208 is disposed between the blood inlet slot 224 and the RBC outlet slot272. That is, preferably no WBCs nor any portion of a bully coat,disposed radially adjacent to the separated RBCs, is allowed to flowbeyond the control port dam 280 and to the control port slot 264. The"buffy coat" includes primarily WBCs, lymphocytes, and the radiallyoutwardmost portion of the platelet layer. As such, substantially onlythe separated RBCs and plasma are removed from the channel 208 via theRBC control slot 264 to maintain interface control as noted.

The flow of RBCs to the control port assembly 488 is typicallyrelatively small. Nonetheless, the ability for this flow is highlydesired in that the control port assembly 488 functions in combinationwith the RBC outlet port assembly 516 to automatically control theradial position of an interface between separated RBCs and the "buffycoat" in relation to the RBC dam 232 by controlling the radial positionof an interface between separated RBCs and plasma in relation to thecontrol port assembly 488. The control port assembly 488 and RBC outletport assembly 516 automatically function to maintain the location of theinterface between the separated RBCs and the buffy coat at a desiredradial location within the channel 208 which is typically adjacent theRBC dam 232 such that there is no spillover of RBCs or the buffy coatbeyond the RBC dam 232. This function is provided by removing separatedRBCs from the channel 208 at a rate which reduces the potential for RBCsand the other large cells as noted flowing beyond the RBC dam 232 andcontaminating the platelet collection.

Separated platelets, which are disposed radially inwardly of the RBClayer and more specifically radially inwardly of the buffy coat, flowbeyond the RBC dam 232 with the plasma (e.g., via platelet-rich plasma)in a clockwise direction. A generally funnel-shaped platelet collectwell 236 is disposed in a clockwise direction from the RBC dam 232 andis used to remove platelets from the channel 208 in the platelet-richplasma. The configuration of the platelet collect well 236 is defined byonly part of the outer channel wall 216. The portion of the plateletcollect well 236 defined by the configuration of the outer channel wall216 includes a lower face 240, a left side face 244, and a right sideface 248. These faces 240, 244, 248 are each substantially planarsurfaces and taper generally outwardly relative to the rotational axis324 and inwardly toward a central region of the platelet collect well236.

The remainder of the platelet collect well 236 is defined by the bloodprocessing vessel 352 when loaded in the channel 208, namely a generallytriangularly-shaped 428 which is disposed above the platelet outlet portassembly 416 to the interior of the blood processing vessel 352 anddiscussed in more detail below. A platelet support recess 249 extendsfurther radially outwardly from those portions of the platelet collectwell 236 defined by the configuration of the outer channel wall 216 andprimarily receives the support 428 associated with the platelet collectport assembly 416. Generally, the upper portion of the support 428 isdisposed below and engages an upper lip 252 of the platelet supportrecess 249, while portions of the fourth face 444 of the support 428 areseated against the two displaced shoulders 252. This positions thesupport 428 when the blood processing vessel 352 is pressurized todirect platelets toward the platelet collect port assembly 416.

The outer channel wall 216 is further configured to receive the plateletcollect tube 424. An upper platelet collect tube recess 254 and a lowerplatelet collect tube recess 255 are disposed yet further radiallyoutwardly from the platelet support recess 249 to provide this function.As such, the platelet collect tube 424 may extend radially outwardlyfrom the outer sidewall 376 of the blood processing vessel 352, extendupwardly through the lower platelet collect tube recess 255 and theupper platelet collect tube recess 254 behind or radially outwardly fromthe support 428, and extend above the channel housing 204.

Platelet-poor plasma continues to flow in a clockwise direction throughthe channel 208 after the platelet collect well 236 and may be removedfrom the channel 208. In this regard, the channel 208 further includes agenerally concave plasma outlet slot 256 which is disposed proximate thesecond end 288 of the channel 208 and intersects the channel 208 at itsinner channel wall 212 in substantially perpendicular fashion (e.g., theplasma outlet slot 256 interfaces with the inner channel wall 212). Aplasma outlet port assembly 452 to the interior of the blood processingvessel 352 is disposed in this plasma outlet slot 256 such that plasmamay be continually removed from the blood processing vessel 352 duringan apheresis procedure (e.g., during continued rotation of the channelhousing 204). This plasma may be collected and/or returned to thedonor/patient 4. In order to increase the number of platelets that areseparated and removed from the vessel 352 in a given apheresisprocedure, the configuration of the channel 208 between the plateletcollect well 236 and the plasma outlet slot 256 may be such thatplatelets which separate from plasma in this portion of the channel 208actually flow in a counterclockwise direction back towards the plateletcollect well 236 for removal from the channel 208. This may be providedbe configuring the outer channel wall 216 such that it extends generallycurvilinearly about the rotational axis 324 from the platelet collectwell 236 to the plasma outlet slot 256 progressing generally inwardlytoward the rotational axis 324 of the channel housing 204. Consequently,the portion of the channel 208 including the platelet collect well 236and extending from the platelet collect well 236 to the second end 288may be referred to as a second stage 316 of the channel 208.

The channel 208 is also configured to provide platelet-poor plasma tothe control port slot 264 and thus to the control port assembly 488 inorder to assist in automatically controlling the interface between theRBCs and the buffy coat in relation to the RBC dam 232. In this regard,the first end 284 of the channel 208 is interconnected with the secondend 288 of the channel 208 by a connector slot 260. With the firstconnector 360 and second connector 368 of the blood processing vessel352 being joined, they may be collectively disposed in this connectorslot 260. As such, a continuous flowpath is provided within the bloodprocessing vessel 352 and, for purposes of the automatic interfacecontrol feature, RBCs may flow to the control port slot 264 in acounterclockwise direction and plasma may flow to the control port slot264 in a clockwise direction. The portion of the channel 208 extendingfrom the first end 284 to the control port slot 264 may be referred toas a third stage 320 of the channel 208.

As noted above, the configuration of the channel 208 isdesirable/important in a number of respects. As such, the dimensions ofone embodiment of the channel 208 are provided herein and which maycontribute to the functions of the channel 208 discussed below. Thedimensions for one embodiment of the channel 208 are identified on FIG.9B. All radius and thicknesses, etc., are expressed in inches.

One of the desired attributes of the channel 208 is that it facilitatesthe loading the of blood processing vessel 352 therein. This is providedby configuring the channel 208 to include a chamfer 210 on both sides ofthe channel 208 along the entire extent thereof. Generally, the chamfer210 extends downwardly and inwardly toward a central portion of thechannel 208 as illustrated, for instance, in FIGS. 12-13. In embodiment,the angle of this chamfer 210 ranges from about 30° to about 60°relative to horizontal, and preferably is about 45°. Moreover, theconfiguration of the channel 208 retains the blood processing vessel 352within the channel 208 throughout the apheresis procedure. This isparticularly relevant in that the channel housing 254 is preferablyrotated a relatively high rotational velocities, such as about 3,000RPM.

Another desirable attribute of the channel 208 is that it provides aself-retaining function for the blood processing vessel 352. Theconfiguration of the channel 208 in at least the first stage 312, andpreferably in the region of the platelet collect well 236 and in theregion of the RBC dam 232 as well, is configured such that the upperportion of the channel 208 includes a restriction (e.g., such that theupper part of the channel 208 in this region has a reduced width inrelation to a lower portion thereof). Although this configuration couldalso be utilized in the portion of the second stage 316 disposed betweenthe platelet collect well 236 and the plasma outlet slot 256, in theillustrated embodiment the width or sedimentation distance of thechannel 208 in this region is less than the width or sedimentationdistance of the channel 208 throughout the entire first stage 312. Thisuse of a "reduced width" can itself sufficiently retain the bloodprocessing vessel 352 in the channel 208 in the "reduced-width" portionof the second stage 316 such that the inner channel wall 212 and outerchannel wall 216 in this portion of the second stage 316 may begenerally planar and vertically extending surfaces.

In the illustrated embodiment and as best illustrated in FIG. 12, thenoted "restriction" in the channel 208 is provided by configuring theouter channel wall 216 with a generally C-shaped profile. In thisportion of the channel 208, the channel 208 includes an upper channelsection 292 having a first width, a mid-channel section 300 having asecond width greater than the first width, and a lower channel section304 having a width less than that of the mid-channel section 300 andwhich is typically equal to that of the upper channel section 292. Thisprofile is provided by an upper lip 296 which extends radially inwardlyfrom the outer channel wall 216 toward, but displaced from, the innerchannel wall 212, and by a lower lip 308 which extends radially inwardlyfrom the outer channel wall 216 toward, but displaced from, the innerchannel wall 212. This lower lip 308 actually defines a portion of thechannel base 220 but does extend entirely from the outer channel wall216 to the inner channel wall 212 such that it defines a notch 218.

When the blood processing vessel 352 is loaded into the channel 208, thefluid-containing volume of the coinciding portion of the bloodprocessing vessel 352 is disposed below the upper channel section 292and is principally contained within the mid-channel section 300. Thatis, the upper lip 296 "hangs over" the fluid-containing volume of theblood processing vessel 352 over at least a portion of its length. Theupper lip 296 thereby functions to retain the blood processing vessel352 within the channel 208 during rotation of the channel housing 204.Moreover, the upper lip 296 reduces the potential for creep bysupporting the vessel 352 proximate the upper seal 380. The upperchannel section 292 and the lower channel section 304 aremulti-functional in that they also serve to receive and support an upperseal 380 and lower seal 384 of the blood processing vessel 352 to adegree such that the stresses induced on these portions of the bloodprocessing vessel 352 during an apheresis procedure are reduced as willbe discussed in more detail below. As can be appreciated, a similarlyconfigured upper lip and lower lip could extend outwardly from the innerchannel wall 212 toward, but displaced from, the outer channel wall 216,alone or in combination with the upper lip 296 and lower lip 308, andstill retain this same general profile for the channel 208 to providethe noted functions.

Another desirable attribute of the channel 208 is that it allows for theuse of blood as the liquid which primes the blood processing vessel 352versus, for instance, saline solutions. Priming with blood allows forthe actual collection of blood components to begin immediately (i.e.,blood used in the prime is separated into blood component types, atleast one of which may be collected). Blood priming is subject to anumber of characterizations in relation to the apheresis system 2 and isbased upon the configuration of the channel 208. For instance, theconfiguration of the channel 208 allows for blood to be the first liquidintroduced into the blood processing vessel 352 which is loaded in thechannel 208. Moreover, the configuration of the channel 208 allowsseparated plasma to flow in a clockwise direction through the channel208 and to reach the control port slot 264 (and thus the control portassembly 488 of the blood processing vessel 352) before any separatedRBCs or any of the other noted large cells flow in the same clockwisedirection beyond the RBC dam 232 and thus into the second stage 316(i.e., a spillover condition). That is, blood priming may be utilizedsince control of the interface between the separated RBCs and the buffycoat is established before any RBCs or WBCs spill over into the secondstage 316. Blood priming may also be characterized as providing bloodand/or blood components to the entire volume of the blood processingvessel 352 prior to any RBCs or any of the other noted large cellsflowing beyond the RBC dam 232 and into the second stage 316.

In order to achieve this desired objective of priming the bloodprocessing vessel 352 with blood, generally the volume of the channel208 which does not have RBCs to the volume of the channel 208 which doeshave RBCs must be less than one-half of one less than the ratio of thehematocrit of the RBCs leaving the channel 208 through the RBC outletport assembly 516 to the hematocrit of the blood being introduced intothe channel 208 through the blood inlet port assembly 388. This may bemathematically expressed as follows:

    V.sub.2 /V.sub.1 <(H.sub.RP /H.sub.IN -1)/2,

where:

V₂ =the volume of the channel 208 containing only plasma orplatelet-rich plasma;

V₁ =the volume of the channel 208 containing RBCs of the first stage 312and third stage 320;

H_(RP) =the hematocrit of the packed RBCs leaving the channel 208through the RBC outlet port assembly 516; and

H_(IN) =the hematocrit of the blood entering the channel 208 through theblood inlet port assembly 388.

This equation assumes that the hematocrit in the RBC volume and iscalculated as (H_(in) +H_(RP))/2. In the case where the H_(IN) is equalto 0.47 and H_(RP) is equal to 0.75, this requires that the ratio of V₁/V₂ be less than 0.30 in order for a blood prime to be possible.

The noted ratio may be further characterized as the ratio of thatportion of the channel 208 which may be characterized as containingprimarily plasma (e.g., V_(PL)) to the volume of that portion of thechannel 208 which may be characterized as containing primarily RBCs(e.g., V_(RBC) ). Referring to FIG. 15, these respective volumes may bedefined by a reference circle 332 which originates at the rotationalaxis 324 and which intersects the RBC dam 232 at the illustratedlocation which would be at the border of a spillover condition. Portionsof the channel 208 which are disposed outside of this reference circle232 are defined as that portion of the channel 208 which includesprimarily RBCs or which defines V_(RBC) (e.g., about 77.85 cc in theillustrated embodiment), while those portions of the channel 208 whichare disposed inside of the reference circle 232 are defined as thatportion of the channel 208 which includes primarily plasma or whichdefines V_(PL) (e.g., about 19.6 cc in the illustrated embodiment). Inthe illustrated embodiment, the ratio of V_(PL) /V_(RBC) is about 0.25which is less than that noted above for the theoretical calculation forthe blood prime (i.e., 0.30 based upon comparison of the hematocrits).In order to further achieving the noted desired ratio, the width andheight of the channel 208 throughout that portion of the second stage316 disposed in a clockwise direction from the platelet collect well236, also in third stage 320, are each less than the width and height ofthe channel 208 throughout the entire first stage 312.

Another important feature relating to the configuration of the channel208 is that the radially inwardmost portion of the inner channel wall212 is at the interface with the plasma outlet slot 256. That is, theentirety of the inner channel wall 212 slopes toward the plasma outletslot 256. This allows any air which is present in the blood processingvessel 352 during priming to be removed from the blood processing vessel352 through the plasma outlet slot 256 and more specifically the plasmaoutlet port assembly 452 since the air will be the least dense fluidwithin the blood processing vessel 352 at this time.

Another desirable attribute of the channel 208 is that it contributes tobeing able to utilize a high packing factor in an apheresis procedure. A"packing factor" is a dimensionless quantification of the degree ofpacking of the various blood component types in the first stage 312 andis thus reflective of the spacings between the various blood componenttypes. The packing factor may thus be viewed similarly to a theoreticaldensity of sorts (e.g., given a quantity of space, what is the maximumnumber of a particular blood component type that can be contained inthis space).

The packing factor is more specifically defined by the followingequation:

    PF=ω.sup.2 ×R×(v.sub.RBC /W)×V/Q.sub.IN,

where:

PF=packing factor;

ω=rotational velocity;

R=the average radius of the outer channel wall 216 in the first cellseparation stage 312;

v_(RBC) =the sedimentation velocity of RBCs at 1G;

V=the functional volume of the first cell separation stage 312;

W=the average sedimentation distance or width of the channel 208; and

Q_(IN) =the total inlet flow to the channel 208.

Consequently, the packing factor as used herein is dependent upon notonly the configuration of the channel 208, particularly the first stage312, but the rotational velocities being used in the apheresis procedureas well as the inlet flow to the blood processing vessel 352. Thefollowing are packing factors associated with the blood processingchannel 208 having the above-described dimensions:

    ______________________________________                                                N    Q.sub.in                                                                              V            G     P@R1st                                        (rpm)                                                                              ml/mi   (ml)   PF    @R.sub.avg                                                                          (psi)                                 ______________________________________                                                    0    0       62.8 0.0   0.0   0.0                                            905   5       62.8 13.0  100.1 8.1                                           1279   10      62.8 13.0  200.2 16.2                                          1567   15      62.8 13.0  300.2 24.3                                          1809   20      62.8 13.0  400.3 32.5                                          2023   25      62.8 13.0  500.4 40.6                                          2216   30      62.8 13.0  600.5 48.7                                FF8       2394   35      62.8 13.0  700.6 56.8                                SLOPE = .02                                                                             2559   40      62.8 13.0  800.6 64.9                                          2714   45      62.8 13.0  900.7 73.0                                          2861   50      62.8 13.0  1100.9                                                                              81.1                                          3001   55      62.8 13.0  1100.9                                                                              89.3                                          3001   60      62.8 11.9  1100.9                                                                              89.3                                          3001   65      62.8 11.0  1100.9                                                                              89.3                                          3001   70      62.8 10.2  1100.9                                                                              89.3                                          3001   75      62.8 9.5   1100.9                                                                              89.3                                          3001   80      62.8 8.9   1100.9                                                                              89.3                                          3001   85      62.8 8.4   1100.9                                                                              89.3                                          3001   90      62.8 7.9   1100.9                                                                              89.3                                          3001   95      62.8 7.5   1100.9                                                                              89.3                                          3001   100     62.8 7.1   1100.9                                                                              89.3                                          3001   105     62.8 6.8   1100.9                                                                              89.3                                          3001   110     62.8 6.5   1100.9                                                                              89.3                                          3001   115     62.8 6.2   1100.9                                                                              89.3                                          3001   120     62.8 6.0   1100.9                                                                              89.3                                          3001   125     62.8 5.7   1100.9                                                                              89.3                                          3001   130     62.8 5.5   1100.9                                                                              89.3                                          3001   135     62.8 5.3   1100.9                                                                              89.3                                          3001   140     62.8 5.1   1100.9                                                                              89.3                                ______________________________________                                         Note the G forces are listed for the various rotational speeds           

Note the G forces are listed for the various rotational speeds at themiddle of the first stage 312 and for a 10 inch outer diameter for thechannel housing 204. At about 2,560 RPM, the G force is about 800 G,while at about 3,000 RPM the G force is about 1,100 Gs.

Increasing the packing factor beyond a certain point producesdiminishing returns regarding the collection of blood component types.That is, further increases in packing factor may not producecorrespondingly increased collection efficiencies and may in fact impedethe collection of blood component types. It is believed that a packingfactor ranging from about 11 to about 15, and more preferably about 13,is optimum for collection of blood component types. As such, therotational velocity of the channel housing 204 may be adjusted basedupon the inlet flows being provided to the blood processing vessel 352to maintain the packing factor. For instance, the desired operatingspeed for the centrifuge housing 204 during the normal course of anapheresis procedure is about 3,000 RPM. However, this rotational speedmay be reduced to "match" the inlet flow to the blood processing vessel352 in order to retain the desired packing factor. Similarly, therotational speed of the channel housing 204 may be increased to "match"an increased inlet flow to the blood processing vessel 352 in order toretain the desired packing factor.

Due to constraints regarding the blood processing vessel 352, morespecifically the various tubes interconnected therewith (e.g., whichprovide the seal-less loop), the above-noted desired packing factor ofabout 13 may be realized for inlet flows of up to about 55 ml/min.(instantaneous). Beyond 55 ml/min., the rotational speed would have tobe increased above 3000 RMP to maintain the desired packing factor ofabout 13. Although tubes exist which will withstand those rotationalspeeds, presently they are not approved for use in an apheresis system.With the presently approved tubing, the packing factor may be maintainedat a minimum of about 10, and preferably at least about 10.2, for inletflows (instantaneous) of about 40-70 ml/min.

At the above noted increased rotational speeds, the channel 208 not onlyprovides for achieving an increased packing factor, but reduces theimpact of this high packing factor on the collection efficiencyregarding platelet collection. Specifically, the configuration of thechannel 208 is selected to reduce the number of platelets that areretained within the first stage 312. The configuration of the channel208 in the first stage 208 utilizes a progressively reduced width orsedimentation distance progressing from the blood inlet slot 224 to theRBC dam 232. That is, the width of the channel 208 proximate the bloodinlet slot 224 is less than the width of the channel 208 proximate theRBC dam 232. This configuration of the channel 208 in the first stage312 reduces the volume of the "buffy coat" or more specifically layerbetween the RBCs and platelets to be collected. As noted, this buffycoat includes primarily WBCs and lymphocytes, as well as the radiallyoutwardmost portion of the platelet layer. The "buffy coat" ispreferably retained in the first stage 312 during an apheresisprocedure. Since the volume of the "buffy coat" is reduced by thereduced width of the channel 208 proximate the RBC dam 232, this reducesthe number of platelets which are retained in the first stage 312, andthus increases the number of platelets which flow to the plateletcollect well 236.

Disposable Set: Blood Processing Vessel

The blood processing vessel 352 is disposed within the channel 208 fordirectly interfacing with and receiving a flow of blood in an apheresisprocedure. The use of the blood processing vessel 352 alleviates theneed for sterilization of the channel housing 204 after each apheresisprocedure and the vessel 352 may be discarded to provide a disposablesystem. There are initially two important characteristics regarding theoverall structure of the blood processing vessel 352. The bloodprocessing vessel 352 is constructed such that it is sufficiently rigidto be free standing in the channel 208. Moreover, the blood processingvessel 352 is also sufficiently rigid so as to loaded in the channel 208having the above-identified configuration (i.e., such that the bloodprocessing vessel 352 must be directed through the reduced width upperchannel section 292 before passage into the larger width midchannelsection 300). However, the blood processing vessel 352 must also besufficiently flexible so as to substantially conform to the shape of thechannel 208 during an apheresis procedure.

In order to achieve the above-noted characteristics, the bloodprocessing vessel 352 may be constructed as follows. Initially,materials for the blood processing vessel 352 include PVC, PETG, andpolyolefins, with PVC being preferred. Moreover, the wall of thicknessof the blood processing vessel 352 will typically range between about0.030" and 0.040". Furthermore, the durometer rating of the body of theblood processing vessel 352 will generally range from about 50 Shore Ato about 90 Shore A.

Referring primarily to FIGS. 16-23B, the blood processing vessel 352includes a first end 356 and a second end 364 which overlaps with thefirst end 356 and is radially spaced therefrom. A first connector 360 isdisposed proximate the first end 356 and a second connector 368 isdisposed proximate the second end 364. When the first connector 360 andsecond connector 368 are engaged (typically permanently), a continuousflow path is available through the blood processing vessel 352. Thisconstruction of the blood processing vessel 352 facilitates loading inthe channel 208 in the proper position and as noted also contributes tothe automatic control of the interface between the separated RBCs andthe buffy coat relative to the RBC dam 232.

The blood processing vessel 352 includes an inner sidewall 372 and anouter sidewall 376. In the illustrated embodiment, the blood processingvessel 352 is formed by sealing two pieces of material together (e.g.,RF welding). More specifically, the inner sidewall 372 and outersidewall 376 are connected along the entire length of the bloodprocessing vessel 352 to define an upper seal 380 and a lower seal 384.Seals are also provided on the ends of the vessel 352. The upper seal380 is disposed in the reduced width upper channel section 292 of thechannel 208, while the lower seal 384 is disposed in the reduced widthlower channel section 304 of the channel 208 (e.g., FIG. 19F). Thisagain reduces the stresses on the upper seal 380 and lower seal 384 whena flow of blood is provided to the blood processing vessel 352 andpressurizes the same. That is, the upper seal 380 and lower seal 384 areeffectively supported by the channel 208 during an apheresis proceduresuch that a resistance is provided to a "pulling apart" of the upperseal 380 and lower seal 384. By utilizing two separate sheets to formthe blood processing vessel 352, a "flatter" profile may also beachieved. This type of profile is beneficial during rinseback, and alsofacilitates loading and unloading of the vessel 352 relative to thechannel 208.

Blood is introduced into the interior of the blood processing vessel 352through a blood inlet port assembly 388 which is more particularlyillustrated in FIGS. 19A-G. Initially, the port 392, as all other ports,is welded to the blood processing vessel 352 over a relatively smallarea. This results in less movement of materials due to the weldingprocedure which provides a smoother surface for engagement by the bloodand/or blood component types.

The blood inlet port assembly 388 includes a blood inlet port 392 and ablood inlet tube 412 which is fluidly interconnected therewithexteriorly of the blood processing vessel 352. The blood inlet port 392extends through and beyond the inner sidewall 372 of the bloodprocessing vessel 352 into an interior portion of the blood processingvessel 352. Generally, the blood inlet port assembly 388 is structuredto allow blood to be introduced into the blood processing vessel 352during an apheresis procedure without substantially adversely affectingthe operation of the apheresis system 2.

The blood inlet port 392 includes a substantially cylindrical sidewall396. A generally vertically extending slot 404 is disposed proximate anend of the sidewall 396 of the blood inlet port 392 such that the slot404 is substantially parallel with the inner sidewall 372 and outersidewall 376 of the blood processing vessel 352. The slot 404 projectsin the clockwise direction, and thus directs the flow of blood in thechannel 208 generally toward the RBC dam 232. A vane 400 is positionedon the end of the cylindrical sidewall 396, is disposed to besubstantially parallel with the inner sidewall 372, and thereby directsthe flow of blood out through the slot 404. As illustrated in FIG. 19D,the vane 400 includes a generally V-shaped notch on the interior of theblood inlet port 392, the arcuate extent of which defines the "height"of the slot 404.

The desired manner of flow of blood into the blood processing vessel 352during an apheresis procedure is subject to a number ofcharacterizations, each of which is provided by the above-describedblood inlet port assembly 388. Initially, the flow of blood into theblood processing vessel may be characterized as being at an angle ofless than 90° relative a reference line which is perpendicular to theinner sidewall 372 of the blood processing vessel 352. That is, theblood is injected in a direction which is at least partially in thedirection of the desired flow of blood through the blood processingvessel 352. Moreover, the desired flow of blood into the bloodprocessing vessel 352 may be characterized as that which reduces theeffect on other flow characteristics within blood processing vessel 352at the blood inlet port 392.

Separated RBCs 556 again flow along the outer sidewall 376 of the bloodprocessing vessel 352 adjacent the outer channel wall 216, past theblood inlet port 392, and to the RBC outlet port assembly 516 asillustrated in FIGS. 19E and 19G. The desired flow of blood into theblood processing vessel 352 may then be further characterized as thatwhich is substantially parallel with at least one other flow in theregion of the blood inlet port 392 (e.g., inject the blood substantiallyparallel with the flow of RBCs 556). This manner of introducing bloodinto the blood processing vessel 352 may then be further characterizedas that which does not significantly impact at least one other flow inthe region of the blood inlet port 392.

As noted above, the blood inlet port assembly 388 interfaces with theinner sidewall 372 of the blood processing vessel 352 in a manner whichminimizes the discontinuity along the inner channel wall 212 in theregion of the blood inlet slot 224 in which the blood inlet port 392 isdisposed. Specifically, a shield 408 may be integrally formed with anddisposed about the blood inlet port 392. The shield 408 is disposed onan exterior surface of the blood processing vessel 352 and interfaceswith its inner sidewall 372. The shield 408 is at least in partialoverlapping relation with the inner sidewall 372. Moreover, in the casewhere the shield 408 is integrally formed with the port 392, it need notbe attached to the inner sidewall 372. The port 392 is installedasymmetrical relative to the shield 408 which is beneficial formanufacturability. All shields and their blood-related ports discussedbelow also include this feature.

Generally, the shield 408 is more rigid than the inner sidewall 372 ofthe blood processing vessel 352. This increased rigidity may be providedby utilizing a more rigid material for the shield 408 than is used forthe inner sidewall 372. For instance, the durometer rating of thematerial forming the shield 408 may range from about 90 Shore A to about130 Shore A, while the durometer rating of the material forming theinner sidewall 372 of the blood processing vessel 352 again ranges fromabout 50 Shore A to about 90 Shore A in one embodiment. This durometerrating (when the shield 408 and port 392 are integrally formed) alsoenhances the seal between the port 392 and the tube installed therein.

When the blood inlet port 392 is disposed in the blood inlet slot 224when loading the blood processing vessel 352 in the channel 208, theshield 408 is positioned within the recess 228 formed in the innerchannel wall 212. Again, the blood inlet slot 224 intersects with theinner channel wall 212, and more specifically the recess 228. That is,the recess 228 contains and is disposed about one end of the blood inletslot 224. Preferably, the thickness of the shield 408 is substantiallyequal to the depth or thickness of the recess 228 such that the amountof discontinuity along the inner channel wall 212 in the region of theblood inlet slot 224 is reduced or minimized. Due to the increasedrigidity of the shield 408 in comparison to the materials forming theblood processing vessel 352, when the blood processing vessel 352 ispressurized during an apheresis procedure the shield 408 restrictsmovement of the blood processing vessel 352 and/or the blood inlet port392 into the blood inlet slot 224. That is, the shield 408 restricts andpreferably minimizes any deflection of the blood processing vessel 352into the blood inlet slot 224 during the procedure. Moreover, with theshield 408 being integrally formed with the blood inlet port 392, theradial position of the vertical slot 404 in the blood inlet port 392 isnot dependent upon the thickness of the materials forming the bloodprocessing vessel 352.

In the first stage 312, blood which is provided to the blood processingvessel 352 by the blood inlet port assembly 388 is separated into RBCs,WBCs, platelets, and plasma. The RBCs, as well as the WBCs, are retainedwithin the first stage 312 and are preferably precluded from flowing ina clockwise direction past the RBC dam 232 into the platelet collectwell 236. Instead, the RBCs and WBCs are induced to flow along the outerchannel wall 216 in a counterclockwise direction past the blood inletport 392 and toward the RBC outlet port assembly 516 of the bloodprocessing vessel 352. That is the RBC outlet port assembly 516 isdisposed in a counterclockwise direction from the blood inlet portassembly 388. However, as noted above, the control port dam 280 impedesthe flow buffy coat control port assembly 488 to provide a sharpinterface between the separated RBCs and the plasma proximate thecontrol port assembly 488 such that this may be used to control theradial position of the interface between the RBCs and the bully coat inthe area of the RBC dam 232.

The RBC outlet port assembly 516 is more specifically illustrated inFIGS. 20A-D and generally includes an RBC outlet port 520 and an RBCoutlet tube 540 fluidly interconnected therewith exteriorly of the bloodprocessing vessel 352. The RBC outlet port 520 extends through andbeyond the inner sidewall 372 of the blood processing vessel 352 into aninterior portion of the blood processing vessel 352. In addition toremoving separated RBCs from the blood processing vessel 352 during anapheresis procedure, the RBC outlet port assembly 516 also functions incombination with the control port assembly 488 to automatically controlthe radial position of the interface between separated RBCs and thebuffy coat relative to the RBC dam 232 (e.g., to prevent RBCs fromflowing beyond the RBC dam 232) in a manner discussed in more detailbelow.

The RBC outlet port 520 is also configured to reduce the potential forthe flow therethrough being obstructed during rinseback (i.e., during anattempted evacuation of the blood processing vessel 352 upon completionof blood component separation so as to provide as much of the contentsthereof back to the donor/patient 4). During rinseback, the rotation ofthe channel housing 204 is terminated and a relatively significantdrawing action (e.g., by pumping) is utilized to attempt to remove allcontents from the blood processing vessel 352. The end of the RBC outletport 520 includes a first protrusion 524 and a second protrusion 528displaced therefrom, with a central recess 532 being disposedtherebetween which contains the noted orifice 536 for the blood outletport 520. The first protrusion 524 and the second protrusion 528 eachextend further beyond the inner sidewall 372 of the blood processingvessel 352 a greater distance then the central recess 532. As such,during rinseback if the outer sidewall 376 attempts to contact the innersidewall 372, the first protrusion 524 and second protrusion 528 willdisplace the central recess 532 and its orifice 536 away from the outersidewall 376. This retains the orifice 536 in an open condition suchthat the flow therethrough is not obstructed during rinseback.

As noted above, the RBC outlet port assembly 516 interfaces with theinner sidewall 372 of the blood processing vessel 352 in a manner whichminimizes the discontinuity along the inner channel wall 212 in theregion of the RBC outlet 272 in which the RBC outlet port 520 isdisposed. Specifically, a shield 538 is integrally formed with anddisposed about the RBC outlet port 520. The shield 538 is disposed on anexterior surface of the blood processing vessel 352 and interfaces withits inner sidewall 372. The shield 538 is at least in partialover-lapping relation with the inner sidewall 372. Moreover, in the casewhere the shield 538 is integrally formed with the port 520, it need notbe attached to the inner sidewall 372. Generally, the shield 538 is morerigid than the inner sidewall 372. This increased rigidity may beprovided by utilizing a more rigid material for the shield 538 than isused for the inner sidewall 372. For instance, the durometer rating ofthe material forming the shield 538 may range from about 90 Shore A toabout 130 Shore A, while the durometer rating of the material formingthe inner sidewall 372 of the blood processing vessel 352 again rangesfrom about 50 Shore A to about 90 Shore A in one embodiment.

When the RBC outlet port 520 is disposed in the RBC outlet slot 272 whenloading the blood processing vessel 352 in the channel 208, the shield538 is positioned within the recess 276 formed in the inner channel wall212. Again, the RBC outlet slot 272 intersects with the inner channelwall 212, and more specifically the recess 276. That is, the recess 276contains and is disposed about one end of the RBC outlet slot 272.Preferably, the thickness of the shield 538 is substantially equal tothe depth or thickness of the recess 276 such that the amount ofdiscontinuity along the inner channel wall 212 in the region of the RBCoutlet slot 272 is reduced or minimized. Due to the increased rigidityof the shield 538 in comparison to the materials forming the bloodprocessing vessel 352, when the blood processing vessel 352 ispressurized during an apheresis procedure, the shield 538 restrictsmovement of the blood processing vessel 352 and/or the RBC outlet port520 into the RBC outlet slot 272. That is, the shield 538 restricts andpreferably minimizes any deflection of the blood processing vessel 352into the RBC outlet slot 272. Moreover, with the shield 538 beingintegrally formed with the RBC outlet port 520, the radial position ofthe orifice 536 is not dependent upon the thickness of the materialsforming the blood processing vessel 352.

Separated platelets are allowed to flow beyond the RBC dam 232 and intothe second stage 316 of the channel 208 in platelet-rich plasma. Theblood processing vessel 352 includes a platelet collect port assembly416 to continually remove these platelets from the vessel 352 throughoutan apheresis procedure and such is more particularly illustrated inFIGS. 8, 16, and 21A-B. Generally, the platelet collect port assembly416 is disposed in a clockwise direction from the blood inlet portassembly 388, as well as from the RBC dam 232 when the blood processingvessel 352 is loaded into the channel 208. Moreover, the plateletcollect port assembly 416 interfaces with the outer sidewall 376 of theblood processing vessel 352.

The platelet collect port assembly 416 is disposed in the plateletsupport recess 249 and the platelet outlet tube recess 254 which aredisposed radially outwardly from the portion of the platelet collectwell 236 defined by the outer channel wall 216 of the channel 208. Theplatelet collect port assembly 416 generally includes a platelet collectport 420 and a platelet collect tube 424 which is fluidly interconnectedtherewith exteriorly of the blood processing vessel 352. The orifice 422of the port 420 may be substantially flush with the interior surface ofthe outer sidewall 376 of the blood processing vessel 352. Moreover, theradial position of the orifice 422 is established by engagement of partof the platelet collect port 420 with boundaries of the recess 249and/or 254.

The platelet collect port 420 is welded to the blood processing vessel352. The thickness of the overlapping portions of the port 420 andvessel 352 are substantially equal. The weld area is overheated suchthat there is a mixing of the two materials. This results in theplatelet collect port 420 being able to flex substantially against theouter channel wall 216 when the vessel 352 is pressurized.

The blood processing vessel 352 and the outer channel wall 216 of thechannel 210 collectively define the platelet collect well 236. Thecontribution of the blood processing vessel 352 to the platelet collectwell 236 is provided by a substantially rigid support 428 which isdisposed vertically above the platelet collect port 420 and hingedlyinterconnected at location 430 with the outer sidewall 376 and/or amounting plate 426 of the platelet collect port 420. The contouredsupport 428 includes a first face 432 and a second face 436 whichinterface with the exterior surface of the outer sidewall 376 of theblood processing vessel 352 (i.e., the support overlaps with thesidewall 376 of the blood processing vessel 352 and need not be attachedthereto over the entire interface therewith) and which are disposed indifferent angular positions. The upper portion of the first face 432extends over the top of the blood processing vessel 352, while the lowerportion of the first face 432 generally coincides with the upper seal380 on the blood processing vessel 352. The second face 436 interfaceswith the outer sidewall 376 in a region of the fluid-containing volumeof the blood processing vessel 352 and is the primary surface whichdirects platelets toward the platelet collect port 420.

When the blood processing vessel 352 is pressurized, the support 428moves into a predetermined position defined by portions of the plateletcollect recess 252. Specifically, a third face 440 is retained under anupper lip 254 on the upper perimeter of the platelet support recess 249,and the two sides of a fourth face 444 seat against a shoulder 252disposed on each side of the platelet support recess 249. A platelettubing notch 448 is formed in the support 428 at generally theintersection between the third face 440 and the fourth face 444. Theplatelet collect tube 426 thus may extend out from the platelet collectport 420, up the platelet collect tube recess 254, against the platelettube notch 448 if necessary, and above the channel housing 204 to passdown through the central opening 328 therein.

In order to increase the purity of platelets that are collected, aplatelet purification system as described in U.S. patent applicationSer. Nos. 08/423,578 and 08/423,583 may be disposed in the plateletcollect tube 424, and the entire disclosures of these patentapplications is incorporated by reference in their entirety herein.

Platelet-poor plasma flows beyond the platelet collect well 236 and tothe plasma outlet port assembly 452. Here, some of the platelet-poorplasma may be removed from the blood processing vessel 352 andcollected, although this "separated" plasma may also be returned thedonor/patient 4 in some instances. The plasma port 456 is also used inthe blood priming of the vessel 352 in that air is removed from thevessel 352 through the plasma port 456. Referring to FIG. 22, the plasmaoutlet port assembly 452 includes a plasma outlet port 456 and a plasmaoutlet tube 476 which is fluidly interconnected therewith exteriorly ofthe blood processing vessel 352. The plasma outlet port 456 extendsthrough and beyond the inner sidewall 372 of the blood processing vessel352 into an interior of the blood processing vessel 352. The plasmaoutlet port 456 is disposed between the second end 364 of the bloodprocessing vessel 352 and the second connector 368.

The plasma outlet port 456 is configured to reduce the potential for theflow therethrough being obstructed during rinseback (i.e., during anattempted evacuation of the blood processing vessel 352 upon completionof an apheresis procedure so as to provide as much of the contentsthereof back to the donor/patient 4). During rinseback, the rotation ofthe channel housing 204 is terminated and a relatively significantdrawing action (e.g., by pumping) is utilized to attempt to remove allcontents from the blood processing vessel 352. The end of the plasmaoutlet port 456 includes a first protrusion 460 and a second protrusion464 displaced therefrom, with a central recess 468 being disposedtherebetween which contains an orifice 472 for the plasma outlet port456. The first protrusion 460 and the second protrusion 464 each extendfurther beyond the inner sidewall 372 of the blood processing vessel 352a greater distance then the central recess 468. As such, duringrinseback if the outer sidewall 376 attempts to contact the innersidewall 372, the first protrusion 460 and second protrusion 464 willdisplace the central recess 468 and its orifice 472 away from the outersidewall 376. This retains the orifice 472 in an open condition suchthat the flow therethrough is not obstructed during rinseback.

In order to further assist in withdrawal from the blood processingvessel 352 after completion of an apheresis procedure and thus duringrinseback, a first passageway 480 and a second passageway 484 are formedin the blood processing vessel 352 (e.g., via heat seals, RF seals) andgenerally extend downwardly from the plasma outlet port 456 toward alower portion of the blood processing vessel 352. The first passageway480 and second passageway 484 are disposed on opposite sides of theplasma outlet port 456. With this configuration, a drawing actionthrough the plasma outlet port 456 is initiated in a lower portion ofthe blood processing vessel 352 at two displaced locations.

Some of the separated plasma is also utilized to automatically controlthe location of the interface between separated RBCs and the buffy coatin the first stage 312, specifically the radial position of thisinterface relative to the RBC dam 232. Plasma which provides thisinterface control function is removed from the blood processing vessel352 by a control port assembly 488 which is illustrated in FIGS. 23A-B.The control port assembly 488 is disposed in a clockwise direction fromthe plasma outlet port assembly 452 and proximate the RBC outlet portassembly 516, and thus between the first end 284 of the channel 208 andthe RBC outlet port assembly 516. This plasma thus flows from the secondstage 316 and into the third stage 320 to provide this function.

The control port assembly 488 generally includes a control port 492 andcontrol port tube 512 which is fluidly interconnected therewithexteriorly of the blood processing vessel 352. The control port 492extends through and beyond the inner sidewall 372 of the bloodprocessing vessel 352 into an interior portion of the blood processingvessel 352. The radial positioning of the orifice 504 of the controlport 492 is not dependent upon the thickness of the material forming theblood processing vessel 352. Instead, the control port 492 includes ashoulder 496 which engages or seats upon structure within the controlport slot 264 to accurately place the orifice 504 at a predeterminedradial position within the channel 208. Moreover, this predeterminedradial position is substantially maintained even after the bloodprocessing vessel is pressurized. In this regard, the control portassembly 488 interfaces with the inner sidewall 372 of the bloodprocessing vessel 352 in a manner which minimizes the discontinuityalong the inner channel wall 212 in the region of the control port slot264 in which the control port 492 is disposed. Specifically, a shield508 is integrally formed with and disposed about the control port 492.The shield 508 is disposed on an exterior surface of the bloodprocessing vessel 352 and interfaces with its inner sidewall 372. Theshield 508 is at least in partial overlapping relation with the innersidewall 372. Moreover, in the case where the shield 508 is integrallyformed with the port 492, it need not be attached to the inner sidewall372. Generally, the shield 508 is more rigid than the inner sidewall 372and this assists in maintaining the orifice 504 of the control port 492at the desired radial position within the channel 208. This increasedrigidity may be provided by utilizing a more rigid material for theshield 508 than is used for the inner sidewall 372. For instance, thedurometer rating of the material forming the shield 508 may range fromabout 90 Shore A to about 130 Shore A, while the durometer rating of thematerial forming the inner sidewall 372 of the blood processing vessel352 again ranges from about 50 Shore A to about 90 Shore A in oneembodiment.

The control port assembly 488 and the RBC outlet port assembly 516function in combination to control the radial position of the interfacebetween separated RBCs and the buffy coat relative to the RBC dam 232.Two structural differences between the RBC outlet port assembly 516 andthe control port assembly 488 contribute to achieving this automaticcontrol. Initially, the orifice 536 to the RBC outlet port 520 isdisposed further into the interior of the blood processing vessel 352than the control port 492. In one embodiment, the orifice 536 of the RBCoutlet port 520 is disposed more radially outwardly than the orifice 504of the control port 492. Moreover, the diameter of the RBC outlet tube540 is greater than that of the control port tube 512. In oneembodiment, the inner diameter of the RBC outlet tube 54 is about0.094", while the inner diameter of the control port tube 512 is about0.035". The control port tube 512 and RBC outlet tube 540 also join intoa common return tube 546 via a three-way tubing jack 544 which furtherassists in providing the automatic interface control feature.

The automatic interface position control is provided as followsutilizing the RBC outlet port assembly 516 and the control port assembly488. Initially, there are two interfaces in the channel 208 ofsignificance with regard to this automatic interface position controlfeature. One of these interfaces is the RBC/buffy coat interface inrelation to the RBC dam 232. However, there is also an RBC/plasmainterface in the region of the control port assembly 488 which again isavailable through use of the control port dam 280. The control port dam280 allows substantially only RBCs to flow to the control port assembly488 in a counterclockwise direction.

In the event that the interface between the RBCs and plasma movesradially inwardly toward the rotational axis 324, RBCs will beginflowing out the control port tube 512 in addition to the RBC outlet tube540. This decreases the flow through the smaller diameter control porttube 512 due to the higher viscosity and density of the RBCs compared tothe plasma which typically flows through the control port tube 512.Consequently, the flow through the larger diameter RBC outlet tube 540must increase since the flow through the return tube 546 must remain thesame. This removes more RBCs from the first stage 312 such that both theinterface between the RBCs and the buffy coat in relation to the RBC dam232 and the interface between the RBCs and the plasma both move radiallyoutwardly. That is, this changes the radial position of each of theseinterfaces. As such, the potential for RBCs flowing beyond the RBC dam232 and into the platelet collect well 236 is reduced.

In the event that the location of the interface between the RBCs andplasma progresses radially outward, the flow through the control porttube 512 will increase since the quantity of RBCs exiting the bloodprocessing vessel 352 through the control port 512 will have decreased.Since the flow through the return tube 546 must remain the same, thisresults in a decrease in the flow of RBCs through the RBC outlet tube540. This reduces the number of RBCs being removed from the channel 208such that both the interface between the RBCs and the bully coat inrelation to the RBC dam 232 and the interface between the RBCs and theplasma both move radially inwardly. That is, this changes the radialposition of each of these interfaces.

The above-described tubes which interface with the blood processingvessel 352, namely the blood inlet tube 412, the platelet collect tube424, the plasma outlet tube 476, the return tube 546, each passdownwardly through the central opening 328 in the channel housing 204. Atubing jacket 548 is disposed about these various tubes and protectssuch tubes during rotation of the channel housing 204. These tubes arealso fluidly interconnected with the extracorporeal tubing circuit 10which again provides for fluid communication between the donor/patient 4and the blood processing vessel 352.

The blood processing vessel 352 also includes features for loading andunloading the same from the channel 208. Referring back to FIG. 16, thevessel 352 includes at least one and preferably a plurality of tabs 552.The tabs 552 may be integrally formed with the blood processing vessel352 (e.g., formed by the seal which also forms the upper seal 380).However, the tabs 552 may also be separately attached. The tabs 552nonetheless extend vertically above the fluid-containing volume of theblood processing vessel 352, preferably a distance such that the tabs552 actually project above the channel housing 204. The tabs 552 therebyprovide a convenient non-fluid-containing structure for the operator tograsp and load/remove the blood processing vessel 352 into/from thechannel 208 (i.e., they provide structure for the operator to graspwhich has had no blood-related flow therethrough during the apheresisprocedure). The tabs 552 are particularly useful since there may beresistance provided to a loading and an unloading of the bloodprocessing vessel 352 into/from the channel 208.

Centrifuge Rotor Assembly

The channel assembly 200 is mounted on the centrifuge rotor assembly 568which rotates the channel assembly 200 to separate the blood into thevarious blood component types by centrifugation. The centrifuge rotorassembly 568 is principally illustrated in FIGS. 24-25 and generallyincludes a lower rotor housing 584 having a lower gear 588. An input ordrive shaft 576 is disposed within the lower rotor housing 584 and isrotatably driven by an appropriate motor 572. The input/drive shaft 576includes a platform 580 mounted on an upper portion thereof and a rotorbody 592 is detachably interconnected with the platform 580 such that itwill rotate therewith as the input/drive shaft 576 is rotated by themotor 572.

The centrifuge rotor assembly 568 further includes an upper rotorhousing 632 which includes a mounting ring 644 on which the channelhousing 204 is positioned. In order to allow the channel housing 204 torotate at twice the speed of the rotor body 592, the upper rotor housing632 and lower rotor housing 584 are rotatably interconnected by a pinionassembly 612. The pinion assembly 612 is mounted on the rotor body 592and includes a pinion mounting assembly 616 and a rotatable pinion 620.The pinion 620 interfaces with the lower gear 588 and a driven gear 636which is mounted on the mounting ring 644. The gear ratio is such thatfor every one revolution of the rotor body 592, the upper rotor housing632 rotates twice. This ratio is desired such that no rotary seals arerequired for the tubes interfacing with the blood processing vessel 352.In one embodiment, the lower gear 588, the pinion 620, and the drivengear 636 utilize straight bevel gearing.

The centrifuge rotor assembly 568 is also configured for easy loading ofthe blood processing vessel 352 in the channel 208 of the channelhousing 204. In this regard, the rotor body 592 includes a generallyL-shaped blood processing vessel loading aperture 597. The aperture 597includes a lower aperture 600 which extends generally horizontally intothe rotor body 592 through its sidewall 596 of the rotor body 592, butonly partially therethrough. The perimeter of the lower aperture 600 isdefined by a left concave wall 601, a back concave wall 603, and a rightconcave wall 602.

The loading aperture 597 also includes an upper aperture 598 whichintersects with the lower aperture 600 at 599 and extends upwardlythrough an upper portion of the rotor body 592. The upper aperture 598is aligned with a generally vertically extending central opening 640 inthe upper rotor housing 632. As noted above, the channel housing 204also includes a central opening 328. As such, a blood processing vessel352 may be folded if desired, inserted into the lower aperture 600,deflected upwardly by the back concave wall 603, through the upperaperture 598, through the central opening 640 in the upper rotor housing632, and through the central opening 328 of the channel housing 204. Theoperator may then grasp the blood processing vessel 352 and load thesame in the channel 208.

The centrifuge rotor assembly 568 includes a number of additionalfeatures to facilitate the loading of the blood processing vessel 352 inthe channel 208. Initially, the pinion 620 is radially offset inrelation to the lower aperture 600 of the rotor body 592. In oneembodiment, a reference axis laterally bisects the lower aperture 600and may be referred to as the "zero axis". The axis about which thepinon 620 rotates is displaced from this "zero axis" by an angle α ofabout 40° in the illustrated embodiment. An angle α of -40° could alsobe use. Positioning the pinion 620 at an angle of "greater" than ±40°will result in the pinion 620 beginning to interfere with the access tothe loading aperture 597. Although the angle may be less than 40° andmay even be 0°, having the pinion 620 at 0° will result in thecounterweights 608 potentially interfering with the access to theloading aperture 597. Based upon the foregoing, in FIG. 25 the pinionassembly 612 has therefore been rotated about the axis which thecentrifuge rotor assembly 568 rotates for ease of illustration.

Since only a single drive gear is utilized to rotate the upper rotorhousing 632 relative to the rotor body 592, an upper counterweight 604and lower counterweight 608 are disposed or detachably connected to therotor body 592 proximate the upper and lower extremes of the loweraperture 600. Due to the offset positioning of the pinion 620 inrelation to the lower aperture 600, the upper and lower counterweights604, 608 are also radially offset in relation to the lower aperture 600.That is, the upper and lower counterweights 604, 608 are "off to theside" in relation to the lower aperture 600 such that access thereto isnot substantially affected by the counterweights 604 and 608. A tubemounting arm 624 is also appropriately attached to the rotor body 592and engages the tubing jacket 548. The tubing mounting arm 624 serves tofurther the rotational balance of the rotor body 592.

Another feature of the centrifuge rotor assembly 568 which contributesto the loading of the blood processing vessel 352 upwardly through therotor body 592 is the size of the lower aperture 600. As illustrated inFIG. 25B, the "width" of the lower aperture may be defined by an angle θwhich may range from about 70° to about 90°, and in the illustratedembodiment is about 74°. The back wall 603, left wall 601, and rightwall 602 are also defined by a radius ranging from about 1.75" to about2.250", and in the illustrated embodiment this radius is between about2.008" and about 2.032".

Apheresis Protocol

One protocol which may be followed for performing an apheresis procedureon a donor/patient 4 utilizing the above-described system 2 will now besummarized. Initially, an operator loads the cassette assembly 110 ontothe pump/valve/sensor assembly 1000 of the blood component separationdevice 6 and hangs the various bags (e.g., bags 114, 94, 84) on theblood component separation device 6. The operator then loads the bloodprocessing vessel 352 within the channel 208 which is disposed on thechannel housing 204 which is in turn mounted on the centrifuge rotorassembly 568, particularly the mounting ring 644. More specifically, theoperator may fold the blood processing vessel 352 and insert the sameinto the blood processing vessel loading aperture 597 on the rotor body592. Due to the arcuately-shaped, concave configuration of the loadingaperture 597, specifically the lower aperture 600, the blood processingvessel 352 is deflected upwardly through the upper aperture 598, thecentral opening 640 in the upper rotor housing, and the central opening328 in the channel housing 294. The operator then grasps the bloodprocessing vessel 352 and pulls it upwardly away from the channelhousing 204.

Once the blood processing vessel 352 has been installed up through thecentrifuge rotor assembly 568, the operator loads the blood processingvessel 352 into the channel 208 on the channel housing 204. The operatorgenerally aligns the blood processing vessel 352 relative to the channel208 (e.g., such that the blood inlet port 392 is vertically aligned withthe blood inlet slot 224, such that the platelet collect port 420 isvertically aligned with the platelet support recess 249 and the plateletcollect tube recess 254, such that the plasma outlet port 456 isvertically aligned with the plasma outlet slot 256, such that thecontrol port 492 is vertically aligned with the control port slot 264,and such that the RBC outlet port 520 is vertically aligned with the RBCoutlet slot 272). Once again, the interconnection of the first connector360 and second connector 368, which is preferably fixed, facilitates theloading of the blood processing vessel 352, as well as the existence ofthe chamfer 210.

With the blood processing vessel 352 properly aligned, the operatordirects the blood processing vessel 352 through the reduced width upperchannel section 292 of the channel 208 until the blood processing vessel352 hits the channel base 220. In this case, the longitudinal extent ofthe blood processing vessel 352 located in the portion of the channel208 which includes the first stage 312, the RBC dam 232, and theplatelet collect stage 316 will be disposed as follows: 1) the upperseal 380 will be disposed in the upper channel section 292; 2) thefluid-containing volume of the blood processing vessel 352 will bedisposed in the mid channel section 300; and 3) the lower seal 384 willbe disposed in the lower channel section 304. The above-noted ports willalso be disposed in their respective slots in the channel housing 204 bythe operator at this time. Moreover, the shield 408 associated with theblood inlet port assembly 388 will be disposed in the recess 228associated with the blood inlet slot 224. Similarly, the shield 538associated with the RBC outlet port assembly 516 will be disposed in therecess 276 associated with the RBC outlet slot 272. Furthermore, theshield 508 associated with the control port assembly 488 will bedisposed in the recess 268 associated with the control port slot 264.

With the extracorporeal tubing circuit 10 and the blood processingvessel 352 loaded in the above-described manner, the circuit 10 andvessel 352 are pressure tested to verify that there are no leaks. Thedonor/patient 4 is then fluidly interconnected with the extracorporealtubing circuit 10 (by inserting an access needle 32 into thedonor/patient 4). Moreover, the anticoagulant tubing 54 is primedbetween the anticoagulant supply (which interfaces with the spike dripmember 52) and the manifold 48. Furthermore, blood return tubing 28 isprimed with blood from the donor/patient 4 by running the blood returnperistaltic pump 1090 pump in reverse to draw blood from thedonor/patient 4, through the blood return tubing 28, and into thereservoir 150 until blood is detected by the low level sensor 1320.

The blood processing vessel 352 must also be primed for the apheresisprocedure. In one embodiment, a blood prime may be utilized in thatblood will be the first liquid introduced into the blood processingvessel 352. The flow of blood from the donor/patient 4 to theextracorporeal tubing circuit 10 is initiated with the centrifuge rotorassembly 568 rotating the channel housing 204 at a rotational velocityof from about 150 RPM to about 250 RPM for a rotor diameter of about10", and typically about 200 RPM. This lower rotational velocity notonly reduces the potential for air locks developing the in the bloodprocessing vessel 352, but also minimizes any preheating of the bloodprocessing vessel 352. The rotational velocity in this "first stage"need not be fixed, but may vary.

Once the flow of blood reaches the blood processing vessel 352, therotational speed of the channel housing 204 is increased from about1,500 RPM to about 2,500 RPM for a rotor diameter of about 10",preferably about 2000 RPM, such that blood being provided to the bloodprocessing vessel 352 will be separated into the various blood componenttypes even during the priming procedure. Once again, in this "secondstage", the rotational velocity during need not be fixed, but may vary.In order for a blood prime to be successful, a flow must be provided tothe control port assembly 488 before any RBCs flows beyond the RBC dam232 in a clockwise direction. This is again provided by theconfiguration of the channel 208.

Importantly, during this "second stage" of the blood priming procedure,air present in the blood processing vessel 352 is removed from the bloodprocessing vessel 352 and due to the noted rotational velocities in this"second stage", the potential for air locks is also reduced. Morespecifically, air which is present in the blood processing vessel 352 isless dense than the whole blood and all of its blood component types. Asnoted above, the radially inwardmost portion of the inner channel wall212 is at the intersection between the plasma outlet slot 256 and theinner channel wall 212. Consequently, the air present in the bloodprocessing vessel 352 collects near the plasma outlet port 456 and isremoved from the blood processing vessel 352 through the plasma outlettubing 476, and is provided to the vent bag 114.

When the blood processing vessel 352 contains blood and/or bloodcomponents throughout its entirety, the rotational velocity of thechannel housing 204 is increased to its normal operation speed fromabout 2,750 RPM to about 3,250 RPM for a rotor diameter of about 10",and preferably about 3,000 RPM. This completes the blood primingprocedure.

During the above-noted blood priming procedure, as well as throughoutthe remainder of the apheresis procedure, blood component types areseparated from each other and removed from the blood processing vessel352 on a blood component type basis. At all times during the apheresisprocedure, the flow of whole blood is provided to the blood processingvessel 352 through the blood inlet port assembly 416 and is directed tothe first stage 312. The control port dam 280 again reduces thepotential for blood flowing in a counterclockwise direction in thechannel 208.

In the first stage 312, blood is separated into a plurality of layers ofblood component types including, from the radially outermost layer tothe radially innermost layer, RBCs, WBCs, platelets, and plasma. Assuch, the RBCs sediment against the outer channel wall 216 in the firstcell separation stage 312. By configuring the RBC dam 232 such that itis a section of the channel 210 which extends further inwardly towardthe rotational axis 324 of the of the channel housing 204, this allowsthe RBC dam 232 to retain separated red blood cells in the first stage312.

Separated RBCs are removed from the first stage 312 utilizing theabove-noted configuration of the outer channel wall 216 which inducesthe RBCs to flow in a counterclockwise direction (e.g., generallyopposite to the flow of blood through the first cell separation stage312). That is, the portion of the channel 208 proximate the RBC outletport assembly 516 is disposed further from the rotational axis 324 ofthe channel housing 204 than that portion of the channel 210 proximatethe RBC dam 232. As such, separated RBCs flow through the first stage312 in a counterclockwise direction along the outer channel wall 216,past blood inlet port assembly 388 on the blood processing vessel 352,and to an RBC outlet port assembly 516. Since the vertical slot 404 ofthe blood inlet port 392 is substantially parallel with the innerchannel wall 212, the outer channel wall 216, the inner sidewall 372 ofthe blood processing vessel 352 and the outer sidewall 376 of the bloodprocessing vessel 352, since it directs the flow of blood in a clockwisedirection in the channel 208 and thus toward the RBC dam 232, since itis disposed proximate the inner channel wall 212, the introduction ofblood into the blood processing vessel 352 does not substantially affectthe flow of RBCs along the outer channel wall 216. Consequently, RBCseffectively flow undisturbed past the blood inlet port 392 and to theRBC outlet port assembly 516 for removal from the blood processingvessel 352. These RBCs may either be collected and/or provided back tothe donor/patient 4.

Platelets are less dense then RBCs and are thus able to flow beyond theRBC dam 232 and to the platelet collect well 236 in platelet-rich plasmawhere they are removed from the blood processing vessel 352 by theplatelet collect port assembly 416. Again, the blood processing vessel352 via the support 428 and the outer channel wall 216 collectivelydefine the platelet collect well 236 when the blood processing vessel352 is pressurized. That is, part of the platelet collect well 236 isdefined by the lower face 240 and side faces 244, 248 formed in theouter channel wall 216, while the remainder thereof is defined by thesecond face 436 of the support 428 when the support 428 is moved into apredetermined position within and against portions of platelet supportrecess 249 upon pressurization of the blood processing vessel 352.

Platelet-poor plasma is less dense than the platelets and continues toflow in a clockwise direction through the second stage 316 to the plasmaoutlet port assembly 452 where at least some of the plasma is removedfrom the blood processing vessel 352. This plasma may be collectedand/or returned to the donor/patient 4. However, some of the plasma flowcontinues in the clockwise direction into and through the third stage320 to the control port assembly 488 to provide for automatic control ofthe location of the interface between the RBCs and platelets in theabove-described manner.

Graphical Computer interface

In order to assist an operator in performing the various steps of theprotocol being used in an apheresis procedure with the apheresis system2, the apheresis system 2 further includes a computer graphicalinterface 660 illustrated in FIG. 1. The following description describesan interface for use by an English language speaking operator. For otheroperations and/or languages, the textual portions of the interfacewould, of course, be adapted accordingly. The graphical interface 660includes a computer display 664 which has "touch screen" capabilities.Other appropriate input devices (e.g., keyboard) may also be utilizedalone or in combination the touch screen. For example, a pump pause anda centrifuge stop button of the well known membrane type may beprovided. The graphics interface 660 not only allows the operator toprovide the necessary input to the apheresis system 2 such that theparameters associated with operation of the apheresis system may bedetermined (e.g., data entry to allow determination of various controlparameters associated with the operation of the apheresis system 2), butthe interface 660 also assists the operator by providing pictorials ofat least certain steps of the apheresis procedure. Moreover, theinterface 660 also effectively conveys the status of the apheresisprocedure to the operator. Furthermore, the interface 660 also may beused to activate standardized corrective actions (i.e., such that theoperator need only identify the problem and indicate the same to theinterface 660 which will then direct the apheresis system 2 to correctthe same).

Referring to FIG. 26, at the start of an apheresis procedure a masterscreen 696 is displayed to the operator on the display 664. The masterscreen 696, as well as each of the screens displayed to the operator bythe interface 600, includes a status bar 676. The status bar 676includes a system prep icon set 700. The system prep icon set 700includes load icon 704 (representing the shape of blood componentseparation device 6) with a downwardly extending arrow whichcollectively pictorially conveys to the operator that the disposable set8 must be loaded onto the blood component separation device 6. The word"LOAD" is also positioned below the load icon 704 to provide a shorttextual instruction to the operator of the required action(s).

The system prep icon set 700 also includes an information icon 708(representing the shape of an open filing folder) which pictoriallyconveys to the operator that certain information relating to thedonor/patient 4, the procedure protocol, and/or the blood componentseparation device 6 must be obtained and entered. This information maybe utilized by the apheresis system 2 to calculate one or more of theparameters associated with the apheresis procedure (e.g., inlet flowrate to the blood processing vessel 352) and/or to generate predictedyields of one or more blood component types (e.g., the amount of acertain blood component type which is anticipated to be collected basedupon certain parameters such as donation time). The word "INFO" is alsopositioned below the information icon 708 to provide a short textualinstruction to the operator of the required action(s). The informationicon 708 is also positioned to the right of the load icon 704 toindicate to the operator that it is preferred, although not required, toperform the step(s) associated with the information icon 708 after thestep(s) associated with the load icon 704 have been completed.

The status bar 676 also includes a collection icon set 712. Thecollection icon set 712 includes a donor/patient prep icon 716(representing the shape of the donor/patient 4) which pictoriallyconveys to the operator that the donor/patient 4 must now be fluidlyinterconnected with the blood component separation device 6. The word"PREPARE" is also positioned below the donor/patient prep icon 716 toprovide a short textual instruction to the operator of the requiredaction(s). The donor/patient prep icon 716 is also positioned to theright of the information icon 708 to indicate to the operator that thestep(s) associated with the donor/patient prep icon 716 may only beperformed after the step(s) associated with the load icon 704 and theinformation icon 708 have been completed.

The collection icon set 712 also includes a donate icon 720 with alaterally extending arrow which collectively pictorially conveys to theoperator that the actual collection procedure may be initiated and thatthe step(s) to initiate this action should now be performed. The word"DONATE" is also positioned below the donate icon 720 to provide a shorttextual instruction to the operator of the required action(s). Thedonate prep icon 720 is also positioned to the right of thedonor/patient prep icon 716 to indicate to the operator that the step(s)associated with the donate icon 720 must be performed after the step(s)associated with the donor/patient prep icon 716 have been completed.

The status bar 676 also includes an unload icon 724 (representing theshape of the blood component separation device 6) and a generallyupwardly extending arrow which collectively pictorially convey to theoperator that the disposable set must now be removed from the bloodcomponent separation device 6. The word "UNLOAD" is also positionedbelow the unload icon 724 to provide a short textual instruction to theoperator of the required action(s). The unload icon 724 is alsopositioned to the right of the donate icon 720 to indicate to theoperator that the step(s) associated with the unload icon 724 must beperformed after the step(s) associated with the donate icon 720 havebeen completed.

The system preparation icon set 700, collection icon set 712, and unloadicon 724 in the status bar 676 sequentially set forth certain basicsteps for the apheresis procedure. That is, the left to rightpositioning of the various icons conveys to the operator thedesired/required order in which the step(s) associated with the iconsshould/must be performed. Moreover, the individual icons 704, 708, 716,720,and 724 are also utilized to convey the status of the apheresisprocedure to the operator via three-way color differentiation (i.e., onestatus per color) and/or by three-way shade differentiation. "Shades"includes variations of a given color and also encompasses usingvariations based upon being "lighter" and/or "darker" (e.g., using lightgray, medium gray, and dark gray). That is, a "gray-scale" technique mayalso be utilized and is encompassed by use of color and/or shadedifferentiation.

The first status conveyed to the operator by the icons in the status bar676 is that the step(s) associated with respective icon are not ready tobe performed. That is, the performance of this step(s) would bepremature. This first status is conveyed to the operator by displayingthe associated icon in a first color, such as white. The correspondingtextual description may also be presented in this first color as well.As noted, a first "shade" may also be utilized to convey this firststatus as well.

The second status conveyed to the operator by the icons in the statusbar 676 is that the step(s) associated with the respective icon iseither ready for execution or is in fact currently being executed. Thatis, an indication is provided to the operator that performance of thisstep(s) of the apheresis procedure is now timely. This second status isconveyed to the operator by displaying the associated icon in a secondcolor, such as yellow. The corresponding textual description may also bepresented in this second color as well. As noted, second "shade" mayalso be utilized to convey this second status as well.

The third status conveyed to the operator by the icons in the status bar676 is that the step(s) associated with the respective icon has beenexecuted. That is, an indication is provided to the operator thatperformance of this step(s) of the apheresis procedure has beencompleted. This third status is conveyed to the operator by displayingthe associated icon in a third color, such as gray. The correspondingtextual description may also be presented in this third color as well.As noted, third "shade" may also be utilized to convey this third statusas well.

Based upon the foregoing, it will be appreciated that significantinformation is conveyed to the operator by merely viewing the status bar676. For instance, the operator is provided with a pictorial graphicindicative of the fundamental steps of an apheresis procedure. Moreover,the operator is provided with a textual graphic indicative of thefundamental steps of an apheresis procedure. Furthermore, the operatoris provided with a desired/required order in which these stepsshould/must be performed. Finally, the operator is provided with thestatus of the apheresis procedure via the noted three-way color/shadedifferentiation.

The master screen 696, as well all other screens displayed to theoperator by the interface 660 during an apheresis procedure, alsoinclude a work area 688. The work area 688 provides multiple functions.Initially, the work area 688 displays additional information(pictorially and textually in some instances) on performing theapheresis procedure to the operator (e.g., certain additional substepsof the apheresis procedure, addressing certain "conditions" encounteredduring the apheresis procedure). Moreover, the work area 688 alsodisplays additional information on the status of the apheresis procedureto the operator. Furthermore, the work area 688 also provides foroperator interaction with the computer interface 660, such as byallowing/requiring the operator to input certain information.

Continuing to refer to FIG. 26, the work area 688 of the master screen696 displays a load system button 728 and a donor/patient info button780. The operator may touch either of these buttons 728, 780 (i.e.,since the display 696 has "touch screen" capabilities) to generatefurther screens for providing information to the operator and/or tofacilitate the inputting of information to the computer interface 660.The operator may initially touch either the load system button 728 orthe donor/patient info button 780 at the start of an apheresisprocedure. That is, the order in which the step(s) associated with theload system button 728 are performed in relation to the apheresisstep(s) associated with the donor/patient info button 780 are performedis not important (i.e., the steps associated with the load system button728 may be performed before or after the steps associated with thedonor/patient info button 780). The apheresis procedure will bedescribed with regard to the operator electing to initially activate theload system button 728 via the touch screen feature.

Activation of the load system button 728 generates a loading procedurescreen 732 on the computer display 664 which is illustrated in FIG. 27.The loading procedure screen 732 displays multiple pictorials to theoperator in the work area 688 which relate to the steps which need to beperformed to prepare the blood component separation device 6 for anapheresis procedure. Initially, a hang pictorial 736 is displayed whichpictorially conveys to the operator that the various bags (e.g., an ACbag(s) (not shown), plasma collect bag(s) 94 platelet collect bag(s) 84)need to be hung on the blood component separation device 6 and generallyhow this step may be affected by the operator. The word "HANG" is alsopositioned above the hang pictorial 736 to provide a short textualinstruction to the operator of the required action(s). Consequently,there are two different types of graphical representations provided tothe operator relating to a specific operator action which is required toprepare the blood component separation device 6 for the apheresisprocedure. Moreover, the hang pictorial 736 is disposed on the left sideof the loading procedure screen 732 which indicates that this is thefirst step or substep associated with the load icon 704. In order toprovide further indications of the desired order to the operator, thenumber "1" is also disposed adjacent to the word "HANG."

A focus color (e.g., yellow) or shade may be used to direct theoperator's attention to specific areas of the machine or screen. Theloading procedure screen 732 also displays an insert pictorial 740 tothe operator in the work area 688. The insert pictorial 740 pictoriallyconvey to the operator that the cassette assembly 110 needs to bemounted on the pump/valve/sensor assembly 1000 of the blood componentseparation device 6 and generally how this step may be affected by theoperator. The word "INSERT" is also positioned above the insertpictorial 740 to provide a short textual instruction to the operator ofthe required action(s). The insert pictorial 740 is also positioned tothe right of the hang pictorial 736 to indicate to the operator that itis preferred, although not required, to perform the step(s) associatedwith the insert pictorial 740 after the step(s) associated with the hangpictorial 736 have been completed. In order to provide furtherindications of the desired order to the operator, the number "2" is alsodisposed adjacent to the word "INSERT."

The loading procedure screen 732 also displays a load pictorial 744 tothe operator in the work area 688. The load pictorial 744 pictoriallyconveys to the operator that the blood processing vessel 352 needs to beloaded into the channel 208 of the channel housing 204 on the centrifugerotor assembly 568 and generally how this step may be affected by theoperator. The word "LOAD" is also positioned above the load pictorial744 to provide a short textual instruction to the operator of therequired action(s). The load pictorial 744 is also positioned to theright of the insert pictorial 740 to indicate to the operator that it ispreferred, although not required, to perform the step(s) associated withthe load pictorial 744 after the step(s) associated with the insertpictorial 740 have been completed. In order to provide furtherindications of the desired order to the operator, the number "3" is alsodisposed adjacent to the word "LOAD."

Finally, the loading procedure screen 732 displays a close pictorial748. The close pictorial 748 pictorially conveys to the operator thatthe door of the blood component collection device housing the centrifugerotor assembly 568 needs to be closed and generally how this step may beaffected by the operator. The word "CLOSE" is also positioned above theclose pictorial 748 to provide a short textual instruction to theoperator of the required action(s). The close pictorial 748 is alsopositioned to the right of the load pictorial 744 to indicate to theoperator that it is required to perform the step(s) associated with theclose pictorial 748 after the step(s) associated with the load pictorial744 have been completed. In order to provide further indications of thedesired order to the operator, the number "4" is also disposed adjacentto the word "CLOSE."

In summary, the work area 688 of the loading procedure screen 732 notonly conveys to the operator what type of steps must be performed forthis aspect of the apheresis procedure and generally how to performthese steps, the work area 688 of the loading procedure screen 732 alsospecifies the order in which these steps should be performed by two"methods." Initially, the pictorial graphics 736, 740, 744 and 748 aresequentially displayed in left-to-right fashion to specify thedesired/required order of performance. Moreover, the four steps are alsonumerically identified next to their associated one-word textualdescription.

In the event that the operator requires additional guidance with regardto any of the steps presented on the loading procedure screen 732, theoperator may touch the help button 692 provided on the loading procedurescreen 732. This may display a menu of screens which the operator mayview and/or may sequentially present a number of help screens associatedwith the loading procedure screen 732. FIG. 28 illustrates a help screen764 which relates to the loading of the blood processing vessel 352 intothe channel 208 on the channel housing 204. Note that in the case of thehelp screen 764 the upper portion of the work area 688 of the loadingprocedure screen 732 is retained (i.e., the one word textualdescriptions of the four basic steps and the associated numericalordering identifier). Moreover, the help screen 764 provides theoperator with more detail, in the nature of additional pictorials,regarding one or more aspects of the particular step(s) or substep or inthis case on the loading of the blood processing vessel 352 in thechannel 208. Once the operator exits the help screen 764 via touchingthe continue button 752 on the help screen 764, the operator is returnedto the loading procedure screen 732 of FIG. 22. Various other screens inthe graphics interface 660 may include a help button 692 to provide thistype of feature.

When the operator has completed each of the four steps or substepspresented on the loading procedure screen 732, the operator touches thecontinue button 752 on the bottom of the loading procedure screen 732.In the event that during the time in which the operator is performingthe steps or substeps associated with the loading procedure screen 732the operator wants to return to the begin operations screen 696, theoperator may touch the display screen 664 in the area of the returnbutton 756. The return button 756 may be provided on various of thescreens to return the operator to the previous screen when acceptable.Moreover, in the event that during the time in which the operator isperforming the steps or substeps associated with the loading procedurescreen 732 the operator wants to terminate the loading procedure, theoperator may touch the display screen 664 in the area of the exit loador cancel button 760. The exit load or cancel button 760 may be providedon various of the other screens to provide the operator with the optionto exit the loading procedure where appropriate.

When the operator touches the continue button 752 on the loadingprocedure screen 732, a disposable pressure test screen 768 is producedon the display 664, one embodiment of which is illustrated in FIG. 29.Generally, the disposable pressure test screen 768 pictorially conveysto the operator that certain steps must be undertaken to allow forpressure testing of the disposable set 8 and how this may be affected bythe operator. In this regard, a donor/patient access line clamppictorial 769 pictorially conveys to the operator that the bloodremoval/return tubing assembly 20, specifically the interconnect tubing38, to the donor/patient 4 must be sealed off. A donor/patient sampleline clamp pictorial 770 pictorially conveys to the operator that thesample line of the sample subassembly 46 must also be sealed off aswell. When the operator has completed these steps, the operator touchesthe continue button 752 and a test in progress screen 772 is displayedto the operator to pictorially and textually convey to the operator thatthe testing procedure is underway and such is illustrated in FIG. 30.

After the pressure test of the disposable set 8 is complete, an ACinterconnect screen 776 is produced on the display 664 and oneembodiment of which is illustrated in FIG. 31. The AC interconnectscreen 776 pictorially conveys to the operator that the anticoagulanttubing assembly 50, specifically the spike drip member 52, of theextracorporeal tubing circuit 10 needs to be fluidly interconnected withthe AC bag (not shown), as well as generally how this step may beaffected by the operator. When this step has been completed by theoperator, the operator touches the continue button 752 on the display664.

The AC interconnect is the last of the steps associated with the loadicon 704 such that the operator is returned to the master screen 696.The master screen 696 now reflects the current status of the apheresisprocedure and is illustrated in FIG. 32. That is, the color or shade ofthe load icon 704 is changed from the second color/shade to the thirdcolor/shade to that which indicates that all steps associated with theload icon 704 have been completed by the operator. Moreover, a statuscheck 730 appears on the load system button 728 in the work area 688 aswell. The load system button 728 is grayed out for the duration of theprocedure and thus indicates that the system setup may not be repeated.Consequently, two different types of indications are provided to theoperator of the current status regarding the loading procedure. Thechange in status of the donor/patient data entry portion of theapheresis procedure is also updated by presenting the information icon708 in the status bar 676 in the second color/shade which indicates tothe operator that it is now appropriate to begin this aspect of theapheresis procedure.

The operator enters the information entry portion of the apheresisprocedure by touching the info button 780 on the display 664 of themaster screen 696. This produces a donor/patient data screen 788 on thedisplay 664, one embodiment of which is illustrated in FIG. 33. Thedonor/patient data screen 788 which includes a sex-type button 792, aheight button 796, and a weight button 808. The operator may indicatethe sex of the donor/patient 4 by touching the relevant portion of thesplit sex-type button 792 and the selected sex may be displayed to theoperator (e.g., via color differentiation). Moreover, the operator mayenter the height and weight of the donor/patient 4 by touching theheight button 796 and the weight button 808, respectively. When theheight button 796 and weight button 808 are engaged by the operator, akeypad 804 is superimposed over the button whose information is to beentered as illustrated in FIG. 34. The keypad 804 may be used to enterthe donor/patient's 4 height and weight and this information may also bedisplayed to the operator.

The information entered by the operator on the donor/patient data screen788 is used to calculate, for instance, the donor/patient's 4 totalblood volume which is presented in a total blood volume display 790 onthe donor/patient data screen 788. The donor/patient's 4 total bloodvolume may be utilized in the determination of various parametersassociated with the apheresis procedure and/or in the estimation of thenumber of blood components which are anticipated to be collected in theprocedure. When the operator has completed these data entry procedures,the operator touches the continue button 752 which will be displayed onthe bottom of the donor/patient data screen 788 after all requestedinformation has been input.

A lab data entry screen 810 is generated on the computer display 664after the steps associated with the donor/patient data screen 788 havebeen completed and as indicated by the operator, one embodiment of whichis illustrated in FIG. 35. The lab data entry screen 810 requests theoperator to enter the time for the collection procedure by touching adonation time button 80 which results in the keypad 804 beingsuperimposed over the donation time button 832 (not shown). The donationtime entered by the operator will be displayed on a time display 860,which specifies the duration for the procedure. Moreover, the donationtime entered by the operator may also be displayed on the donation timebutton 840. The donation time is used, for instance, to predict thenumber of the blood component(s) (e.g., platelets, plasma) which isanticipated to be collected during the procedure.

The lab data screen 810 also prompts the operator to enter thedonor/patient's 4 hematocrit by touching a hematocrit button 842. Thisresults in the keypad 804 being superimposed over the hematocrit button842. The operator may then enter the donor/patient's 4 hematocrit (e.g.,as determined via laboratory analysis of a blood sample from thedonor/patient 4) and such may be displayed on the hematocrit button 842.The donor/patient's 4 hematocrit is also utilized by one or more aspectsof the apheresis procedure.

The lab data screen 810 also prompts the operator to enter thedonor/patient's 4 platelet precount by touching a platelet precountbutton 843. This results in the keypad 804 being superimposed over theplatelet precount button 843. The operator may then enter thedonor/patient's 4 platelet precount (e.g., as determined via laboratoryanalysis of a blood sample from the donor/patient 4) and such may bedisplayed on the platelet precount button 843. The donor/patient's 4platelet precount is also utilized by one or more aspects of theapheresis procedure.

Once the operator has entered all of the requested information, theoperator touches the continue button 752 which returns the operator tothe master screen 696 which now reflects the current status of theapheresis procedure and as illustrated in FIG. 36. Since all of thesteps associated with the information icon 708 have now been completed,the color/shade of the information icon 708 is changed from the secondcolor/shade to the third color/shade to convey to the operator that allassociated steps have been completed. Moreover, a status check 784appears on the donor/patient info button 780 in the work area 688 aswell. Consequently, two different types of indications are provided tothe operator of the current status of this aspect of the apheresisprocedure. Moreover, the change in status of the collection icon set 712of the apheresis procedure is updated by changing the color/shade of thedonor/patient prep icon 716 in the status bar 676 from the firstcolor/shade to the second color/shade. A run button 802 is also nowpresented on the master screen 696 such that the steps associated withthe collection icon set 712 may now be undertaken and further such thatpictorial representations of the same may be provided to the operator.

The initial screen for steps associated with the collection icon set 712is a donor/patient prep screen 812A which is illustrated in FIG. 37. Thedonor/patient prep screen 812A pictorially conveys to the operator thesteps which must be undertaken in relation to the donor/patient 4 beingfluidly interconnected with the blood component separation device.Initially, a donor/patient connect pictorial 816 is displayed whichpictorially conveys to the operator that an access needle 32 must beinstalled on the donor/patient 4, as well as generally how this step maybe affected by the operator. The word "CONNECT" is also positioned abovethe donor/patient connect pictorial 816 to provide a short textualinstruction to the operator of the required action(s). The donor/patientconnect pictorial 816 is disposed on the left side of the donor/patientprep screen 812A which indicates that this is the first step or substepassociated with the donor/patient prep icon 716. In order to providefurther indications of the desired order to the operator, the number "1"is also disposed adjacent the word "CONNECT."

The donor/patient prep screen 812A also displays an open pictorial 820on the display 664. The open pictorial 820 pictorially conveys to theoperator that the clamps 42 in the interconnect tubing 38 and the clampin the tubing of the sample subassembly 46 must be removed, as well asgenerally how these steps may be affected by the operator. The word"OPEN" is also positioned above the open flow pictorial 820 to provide ashort textual instruction to the operator of the required action(s). Theopen pictorial 820 is disposed to the right of the donor/patient connectpictorial 816 which indicates that the step(s) associated with the openpictorial 820 should be performed only after the step(s) associated withthe donor/patient connect pictorial 816 have been completed. In order toprovide further indications of the desired order to the operator, thenumber "2" is also disposed adjacent the word "OPEN."

The donor/patient prep screen 812A also displays a flow pictorial 824 onthe display 664. The flow pictorial 824 pictorially conveys to theoperator that there should now be a flow of blood from the donor/patient4 into the blood removal/return tubing assembly 20, specifically theblood removal tubing 22, and in the sample tubing of the samplesubassembly 46. The word "FLOW" is also positioned above the flowpictorial 824 to provide a short textual description to the operator ofwhat should be occurring at this time. The flow pictorial 824 isdisposed to the right of the open pictorial 820 which indicates that theconditions associated with the flow pictorial 824 should occur onlyafter the step(s) associated with the open pictorial 820 have beencompleted. In order to provide further indications of the desired orderto the operator, the number "3" is also disposed adjacent the word"FLOW."

In summary, the work area 688 of the donor/patient prep screen 812A notonly conveys to the operator what type of steps must be performed forthis aspect of the apheresis procedure and how to generally performthese steps, but also specifies the order in which these steps should beperformed by two methods. Initially, the pictorial graphics 816, 820,and 824 are sequentially displayed in left-to-right fashion. Moreover,the three steps are also numerically identified next to their associatedone-word textual description.

Once the operator completes all of the steps associated with thedonor/patient prep screen 812A, the operator touches the continue button752 which results in the display of a second donor/patient prep screen812B as illustrated in FIG. 38. The donor/patient prep screen 812Bincludes a close pictorial 828 which pictorially conveys to the operatorto terminate the flow of blood from the donor/patient 4 to the samplebag of the sample subassembly 46 by clamping the sample line andgenerally how this step may be affected by the operator. The word"CLOSE" is also positioned above the close pictorial 828 to provide ashort textual instruction to the operator of the required action(s). Theclose pictorial 828 is disposed on the left side of the donor/patientprep screen 812B which indicates that this is the first step or substepassociated with the donor/patient prep screen 812B. In order to providean indication that this is in fact, however, the fourth step associatedwith the donor/patient preps, the number "4" is also disposed adjacentthe word "CLOSE."

The donor/patient prep screen 812B also displays a seal pictorial 832 onthe display 664. The seal flow pictorial 832 pictorially conveys to theoperator that the sample line of the sample subassembly 46 should now besealed off and generally how this step may be affected by the operator.The word "SEAL" is also positioned above the seal pictorial 832 toprovide a short textual instruction to the operator of the requiredaction(s). The seal pictorial 832 is disposed to the right of the closepictorial 828 which indicates that the step(s) associated with the sealpictorial 832 should be performed only after the step(s) associated withthe close pictorial 828 have been completed. In order to provide furtherindications of the desired order to the operator, the number "5" is alsodisposed adjacent the word "SEAL" to indicate that this is actually thefifth step associated with the donor/patient preps.

In summary, the work area 688 of the donor/patient prep screen 812B notonly conveys to the operator what type of steps must be performed forthis aspect of the apheresis procedure and how to generally performthese steps, the work area 688 of the donor/patient prep screen 812Balso specifies the order in which these steps should be performed by twomethods. Initially, the pictorials 828, 832, and 836 are sequentiallydisplayed in left-to-right fashion. Moreover, the four steps are alsonumerically identified next to their associated one-word textualdescription.

Once the operator completes all of the donor/patient preps, the operatormay touch the start prime button 846 on the donor/patient prep screen812B which initiates the above-described blood prime of theextracorporeal tubing circuit 10 and blood processing vessel 352 andwhich results in the display of the run screen 844 illustrated in FIG.39. The run screen 844 primarily displays information to the operatorregarding the apheresis procedure. For instance, the run screen 844includes a blood pressure display 848 (i.e., to convey to the operatorthe donor/patient's extracorporeal blood pressure), a platelet collectdisplay 852 (i.e., to convey to the operator an estimate of the numberof platelets which have been currently collected), a plasma collectdisplay 856 (i.e., to convey to the operator the amount of plasma whichhas been currently collected), and a time display 860 (e.g., both theamount of time which has lapsed since the start of the collectionprocedure (the left bar graph and noted time), as well as the amount oftime remaining in the collection procedure (the right bar graph andnoted time). A control button (not shown) may be provided to togglebetween the time remaining display and the start and stop time display.

The run screen 844 may also display, in the case of a single needleprocedure (i.e., where only one needle is utilized to fluidlyinterconnect the donor/patient 4 with the blood component separationdevice 6), whether blood is being withdrawn from the donor/patient 4(e.g., by displaying "draw in progress") or is being returned to thedonor/patient 4 (e.g., by displaying "return in progress"). Thisinformation may be useful to the donor/patient 4 in that if thedonor/patient 4 is attempting to maintain a certain blood pressure bysqueezing an article to assist in removal of blood from thedonor/patient 4, the donor/patient 4 will be provided with an indicationto suspend these actions while blood is being returned to thedonor/patient 4.

During the apheresis procedure, certain conditions may be detected bythe apheresis system 2 which would benefit from an investigation by theoperator. If one of these types of conditions is detected, anappropriate alarm screen is displayed to the operator. One embodiment ofan alarm screen 864 is illustrated in FIG. 40. Initially, the alarmscreen 864 textually conveys a potential problem with the system 2 via aproblem graphic 868. The text may be useful in ensuring that theoperator understands the problem. The alarm screen 864 also includes anaction pictorial 872 which graphically conveys to the operator theaction which should be taken in relation to the problem. These areactions which may be difficult or impossible for the system 2 to takeitself. Finally, the alarm screen includes an inspection results array876 which allows the operator to indicate the results of the inspection.In the illustrated embodiment, the array 876 includes a blood leakbutton 906, a moisture button 908, and a no leak button 910.

Depending upon the selection made by the operator on the inspectionresults array 876, additional questions may be posed to the operator infurther screens which require further investigation and/or which specifythe desired remedial action. For instance, the supplemental alarm screen878 of FIG. 41 may be generated by the operator touching the moisturebutton 908 on the alarm screen 864. The supplemental alarm screen 878includes a remedial action pictorial 912 and remedial action text 914 toconvey to the operator how to correct the identified problem.

The computer interface 660 may also allow the operator to initiate sometype of corrective action based upon observations made by and/orconveyed to the operator. For instance, various screens of the interface660 may include a trouble shooting button 898 which will generate one ormore trouble shooting screens. These trouble shooting screens mayinclude menus or the like to allow the operator to indicate what type ofpotential problem exists.

One embodiment of a trouble shooting screen 880 is presented in FIG. 42.The trouble shooting screen 880 includes a donor/patient tingling button922. This button 922 would be utilized by the operator to attempt toremedy the effects of AC on the donor/patient 4 in response to thedonor/patient indicating a "tingling sensation" or, alternatively, "ACreaction." When the operator hits the "down arrow" of the donor/patienttingling button 922, the system 2 attempts to correct the condition in apredetermined manner (i.e., a predetermined protocol is employedpreferably this protocol does not require operator actions ordecisions). Once the tingling sensation no longer exists, the operatormay use the "up arrow" button to return the bar on the donor/patienttingling button 922 to its original position.

The trouble shooting screen 880 also includes a clumping button 924.This button 924 would be utilized by the operator if any undesiredclumping of the collected product (e.g., platelets) was observed. Whenthe operator hits the "down arrow" of the clumping button 924, thesystem 2 attempts to correct the condition in a predetermined manner(i.e., a predetermined protocol is employed and preferably this protocoldoes not require operator actions or decisions). Once the clumping is nolonger observed by the operator, the operator may use the "up arrow"button to return the bar on the clumping button 924 to its originalposition.

The trouble shooting screen 880 may also include a spillover button 916and an "air in plasma line" button 918. The spillover button 916 wouldbe engaged by the operator if red blood cells were observed in theplatelet outlet tubing 66, in the platelet collect bag 84, and/orflowing beyond the RBC dam 232. Activation of the spillover button 916via the touch screen capabilities would result in the system 2 using apredetermined and preferably automatic protocol is performed by thesystem 2 to correct this condition. Similarly, if the operator observesair in the plasma line 918 and engages the button 918, the system 2again will preferably automatically employ a predetermined protocol tocorrect this condition.

The "other problem button" 920 may be utilized to generate furthertrouble shooting screens to list further problems which may occur in theapheresis procedure. Again, preferably upon the operator touching theassociated button indicative of a particular problem, a predeterminedprotocol will be preferably automatically employed to attempt to correctthe same.

Upon completion of the collection portion of the apheresis procedure,the rinseback screen 884 is produced on the display 664 which indicatesthat the rinseback procedure will now be performed and which isillustrated in FIG. 44. Once the rinseback is completed, the color/shadeof the donate icon 720 changes from the second color to the thirdcolor/shade to indicate that all steps associated with this aspect ofthe apheresis procedure have been completed. Moreover, the color/shadeof the unload icon 724 will also change from the first color/shade tothe second color/shade to indicate to the operator that the step(s)associated therewith may now be performed.

Upon completion of the rinseback, a run finish screen may be produced onthe display 664 to provide the final collection data as illustrated inFIG. 43 (e.g., the associated yields of platelets and plasma collectedduring the procedure) as well as the fact that the procedure is over(e.g., by displaying "run completed"). The operator may then touch thecontinue button 752.

Once the rinseback procedure is completed, an unload screen 892 will bepresented on the display 664 and is illustrated in FIG. 45. The unloadscreen 892 may sequentially display a number of pictorials to theoperator to convey the steps which should be completed to terminate theprocedure. For instance, a seal/detach pictorial 900 may be initiallydisplayed on the unload screen 892 to pictorially convey to the operatorthat the tubes leading to the platelet and plasma collect bag(s) 84, 94should each be sealed such that the platelet and plasma collect bag(s)84, 94 respectively, may be removed. Once the operator touches thecontinue button 752, a disconnect pictorial 902 may be presented on theunload screen 892 to pictorially convey to the operator that the accessneedle 32 should be removed from the donor/patient 4. Once the operatortouches the continue button 752, a remove pictorial 904 is presented onthe unload screen 892 to pictorially convey to the operator that thedisposable set 8 should be removed from the blood component separationdevice 6 and disposed of properly.

The computer interface 660 provides a number of advantages. Forinstance, the computer interface 660 utilizes a three-way color/shadedifferentiation to conveniently convey the status of the apheresisprocedure to the operator. An icon is presented in one color/shade ifthe step(s) associated with the icon are not yet ready to be performed,while the icon is presented in another color/shade if the step(s)associated with the icon are ready to be performed or are beingperformed, while the icon is presented in yet another color/shade if thestep(s) associated with the icon have been completed. Moreover, thecomputer interface 660 provides pictorials to the operator of at leastcertain of the steps of the apheresis procedure. Furthermore, thedesired/required ordering of at least the fundamental steps of theapheresis procedure is conveyed to the operator. Finally, the interface660 allows for correction of certain conditions, which after appropriateoperator input, are remedied by the system 2 in accordance with apredetermined protocol.

The foregoing description of the present invention has been presentedfor purposes of illustration and description. Furthermore, thedescription is not intended to limit the invention to the form disclosedherein. Consequently, variations and modifications commensurate with theabove teachings, and skill and knowledge of the relevant art, are withinthe scope of the present invention. The embodiments describedhereinabove are further intended to explain best modes known ofpracticing the invention and to enable others skilled in the art toutilize the invention in such, or other embodiments and with variousmodifications required by the particular application(s) or use(s) of thepresent invention. It is intended that the appended claims be construedto include alternative embodiments to the extent permitted by the priorart.

What is claimed is:
 1. An extracorporeal system for an apheresis systemcomprising a blood processing channel, said system comprising:a bloodprocessing vessel positionable in said channel and comprising ablood-related port communicating with an interior of said bloodprocessing vessel; and a support interfacing with said blood-relatedport, and further interfacing with an exterior surface of said bloodprocessing vessel in overlapping relation with a portion of said bloodprocessing vessel, wherein said blood processing channel comprises firstand second channel sidewalls, wherein said channel housing furthercomprises a blood-related port slot which intersects with one of saidfirst and second channel sidewalls and a recess formed on said one ofsaid first and second channel sidewalls and containing at least part ofsaid blood-related port slot, wherein said support of said bloodprocessing vessel is positioned within said recess.
 2. A system, asclaimed in claim 1, wherein:said support has a rigidity greater than arigidity of a portion of said blood processing vessel adjacent saidblood-related port.
 3. A system, as claimed in claim 1, wherein:saidsupport is formed from a material having a greater durometer rating thana material forming a main body of said blood processing vessel.
 4. Asystem, as claimed in claim 1, wherein:said support comprises means forreducing a tendency of said blood processing vessel in a region of saidblood-related port to deflect in a direction of a flow out of said bloodprocessing vessel through said blood-related port when said bloodprocessing vessel is pressurized within said blood processing channel.5. A system, as claimed in claim 1, wherein:a thickness of said supportis substantially equal to a thickness of said recess.
 6. Anextracorporeal system for an apheresis system comprising a bloodprocessing channel, said system comprising:a blood processing vesselpositionable in said channel, wherein said blood processing vesselfurther comprises:a blood inlet port; a control port for controlling aradial position of at least one interface between red blood cells and anadjacent blood component type; and a support interfacing with at leastsaid control port, and further interfacing with an exterior surface ofsaid blood processing vessel in overlapping relation with a portion ofsaid blood processing vessel.
 7. A system, as claimed in claim 6,wherein:said support comprises means for disposing said control port ata predetermined position within said blood processing channel andindependent of a portion of said blood processing vessel through whichsaid control port extends.
 8. A system, as claimed in claim 6,wherein:said control port extends beyond an inner wall of said bloodprocessing vessel into an interior of said blood processing vessel. 9.An extracorporeal system for an apheresis system comprising a bloodprocessing channel, said system comprising:a blood processing vesselpositionable in said channel and comprising a blood-related portcommunicating with an interior of said blood processing vessel; and asupport interfacing with said blood-related port, and furtherinterfacing with an exterior surface of said blood processing vessel inoverlapping relation with a portion of said blood processing vessel,wherein said blood-related port comprises at least one of a blood inletport to said blood processing vessel, a red blood cell outlet port tosaid blood processing vessel, and a control port to said bloodprocessing vessel for controlling a radial position of at least oneinterface between red blood cells and an adjacent blood component type.10. A system, as claimed in claim 1, wherein:said support is fixedlyattached to said blood-related port.
 11. A system, as claimed in claim1, wherein:said support is integrally formed with said blood-relatedport.
 12. A system, as claimed in claim 1, wherein:said support isdisposed about said blood-related port.
 13. An extracorporeal system foran apheresis system comprising a blood processing channel, said systemcomprising:a blood processing vessel positionable in said channel andcomprising a blood-related port communicating with an interior of saidblood processing vessel; and a support interfacing with saidblood-related port, and further interfacing with an exterior surface ofsaid blood processing vessel in overlapping relation with a portion ofsaid blood processing vessel, wherein said support comprises means fordisposing said blood-related port at a predetermined position withinsaid blood processing channel and independent of a portion of said bloodprocessing vessel through which said blood-related port extends.
 14. Anextracorporeal system for an apheresis system comprising a bloodprocessing channel, said system comprising:a blood processing vesselpositionable in said channel and comprising a blood-related portcommunicating with an interior of said blood processing vessel; and asupport associated with said blood-related port, and interfacing with anexterior surface of said blood processing vessel in overlapping relationwith a portion of said blood processing vessel, wherein said bloodprocessing channel comprises first and second channel sidewalls, whereinsaid channel housing further comprises a blood-related port slot whichintersects with one of said first and second channel sidewalls and arecess formed on said one of said first and second channel sidewalls andcontaining at least part of said blood-related port slot, wherein saidsupport of said blood processing vessel is positioned within saidrecess.
 15. A system, as claimed in claim 14, wherein:a thickness ofsaid support is substantially equal to a thickness of said recess. 16.An extracorporeal system for an apheresis system comprising a bloodprocessing channel, said system comprising:a blood processing vesselpositionable in said channel and comprising a blood-related portcommunicating with an interior of said blood processing vessel, saidblood processing vessel further comprising a blood inlet port and acontrol port for controlling a radial position of at least one interfacebetween red blood cells and an adjacent blood component type, whereinsaid blood-related port comprises at least said control port; and asupport associated with said blood-related port, and interfacing with anexterior surface of said blood processing vessel in overlapping relationwith a portion of said blood processing vessel.
 17. A system, as claimedin claim 16, wherein:said support comprises means for disposing saidcontrol port at a predetermined position within said blood processingchannel and independent of a portion of said blood processing vesselthrough which said control port extends.
 18. A system, as claimed inclaim 17, wherein:said control port extends beyond an inner wall of saidblood processing vessel into an interior of said blood processingvessel.
 19. An extracorporeal system for an apheresis system comprisinga blood processing channel, said system comprising:a blood processingvessel positionable in said channel and comprising a blood-related portcommunicating with an interior of said blood processing vessel; and asupport associated with said blood-related port, and interfacing with anexterior surface of said blood processing vessel in overlapping relationwith a portion of said blood processing vessel, wherein saidblood-related port comprises at least one of a blood inlet port to saidblood processing vessel, a red blood cell outlet port to said bloodprocessing vessel, and a control port to said blood processing vesselfor controlling a radial position of at least one interface between redblood cells and an adjacent blood component type.